With the chart below will tell you which TomTom GPS (720/920/910/510/ONE/ONE XL) features these units have in common and which ones differ. We hope we can help sort out the confusion and set you in the right direction. Global Phoenix's eBay online store has these models in stock.  Any of these are good buys, you just need to know what would suit you best.  

The TomTom Go Navigator from TomTom is a standalone GPS navigation system for automobile use. It includes the GPS hardware, the display and cpu system, the car mount, external power supplies, and a custom copy of the TomTom Navigator product. This product features a touch screen. It also has its own web site, TomTomGo.com

                                                                        
Screen size                    4.3''                                        4.0''                                          4.0"
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Touch-Screen               Yes                                         Yes                                           Yes
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Traffic Message
w/optional reciever       Yes                                         No                                            No
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Home Dock                   Yes                                         No                                            No
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Text-to-Speech              Yes                                         No                                           Yes
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FM Transmitter            Yes                                          No                                           Yes
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Processor Speed        400 MHz                                400 MHz                                  400 MHz
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Built in Memory           2GB                                       64MB                                       64MB
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Bluetooth                      Yes                                         Yes                                            Yes
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Pre-Loaded Maps   US/CA/PR                               US/CA/PR                               US/CA/PR
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SD Card Slot               Yes                                           Yes                                           Yes

                                                                               
Screen size                       4.3"                                                                      3.5
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Touchscreen                    Yes                                                                       Yes
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Traffic Message
w/ optional reciever         No                                                                        No
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Home dock                       No                                                                        No
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Text-to-speech                 No                                                                        No
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FM transmitter                No                                                                         No
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Processor Speed           266 MHz                                                              266MHz
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Built-in Memory              1GB                                                                   32MB
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Bluetooth                          Yes                                                                       Yes
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Pre-loaded Maps         US/CA/PR                                                           US/CA/PR
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SD Card Slot                     Yes                                                                       Yes

  The features we will be comparing are:

-SD card slot    Does the unit have an SD card slot so that you can upload more data as well as fill the card with MP3's and JPEG's for use during in transit.

-Text-to-Speech directions    This feature is convenient and makes for safer driving.  Text-to-speech means that the GPS unit will speak complete directions to you including street names.  This allows you to spend more time looking at the road, and less time looking at the GPS itself to see which street to turn onto. 

-BlueTooth Compatibility    Many people's personal phones use BlueTooth, and today's GPS unit's, for the right price, feature ways to run your phone calls through your GPS unit.  This is safer, because you won't be fumbling for a small cell phone while you drive.  This feature comes standard on GPS units that have voice-activated controls.  It may be pricey, but it's well worth it.

-Screen Size     Depending on what kind of car you drive, how good your eye-sight is, and how you have to control the functions of your GPS, screen size can make a big difference.  The car-GPS units don't have small screens per se,  but an inch or two can make a big difference.  You should never go below 3.5" for any GPS unit that has a touchscreen.

-FM transmitter    An FM transmitter allows you to hear your radio through your GPS.  This may not seem like a big deal, but if you're using your audio directions features while driving and listening to your radio, you could miss something.  If you run your radio signal through your GPS unit, it will lower the radio volume while it speaks directions to you so you won't miss a thing.

-Pre-loaded Data    This includes maps, as well as POI's.  POI stands for Point Of Interest.  The more of these you have already programmed it, the less work you have to do later.  Prices vary depending on how many POI's are already included in your GPS, but the more the merrier.  Also maps can be pre-loaded too.  Some GPS units only have maps of the U.S., others may include South America and Europe. 

-Built-in memory    This is the amount of memory your GPS has inside for storing data such as extra maps, POI's, MP3's, etc.

-Home dock    A home dock is only available in newer models, but it is an accessory used for connecting the GPS to your computer so you can download information to its memory.  As you download maps and POIs you will also be charging the internal battery making sure you are ready to go the next time out.

-TMC    Traffic Message Channel is an optional feature that gives you real-time updates on traffic and weather.  This can allow the GPS to reroute you around an upcoming traffic jam, or give you a heads up on rain condition further down the road.   This feature costs extra, but the ability to use TMC is what we are highlighting here.

-Touchscreen   Having a touchscreen is a lot better than having to push tiny buttons in order to get more information out of your GPS.  While you're driving you don't want to spend a lot of time finding specific buttons.  A touchscreen eliminates that problem by giving you clear areas to push when you want more information.

-Processor speed    The GPS' processor, just as in a computer, determines how quickly it can perform certain tasks for you.  The faster the better what with all the extra bells and whistles you're probably going to get with your GPS device.  Locking onto satellites and getting traffic info quickly are a direct result of processor speed.

All of the above models are great GPS navigators that will effortlessly guide you to your desired destinations.  All of the basic features remain the same across the board.  Every GPS described above has an SD card slot, pre-loaded US & Canada maps, Internal memory or some size, Bluetooth compatibility, millions of pre-loaded POI's and they're all touchscreens.  Some of the high-end features differ slightly, from Text-to-speech for the Go 720 and Go 910 models to the simpler audible turn-by-turn directions with the Go 510 and ONE and ONE XL models. 
The best model we offer is the Go 720.  It has the most advanced features, and as more and more TomTom GPS units come onto the market, they will also offer more similar features as standard characteristics.  Synching your audible directions and your music are very important, so the Go 720 is the best on the market for that.  The Go 910 isn't far behind, but it doesn't come with a built-in FM transmitter, so you'd be relying on your GPS's speakers for music and directions without being able to wire it through your cars stereo. 
If you're just trying to get from point A to point B, either of the TomTom One models will do.  Once step up from that is the Go 510, which will be faster and have more information on it from the start.  At the top of the list are the Go 910 and the Go 720.  The Go 720 is our best TomTom model and will surely satisfy your travel needs on the road.
 
  Feel free to check out our online eBay store and get all the information on our available products and prices.  There are a lot of details about the products listed above that weren't covered, so go browse around and get the full picture!