What I like about it:   Rigid yet flexible inner padding that adjusts to the shape of most bags.  Roomy pockets in different widths that can accommodate a variety of items.  A sturdy key post that serves as an anchor to easily find keys.  An open design that allows you to expand your bag when needed to accommodate bulkier items and lets your bag assume its natural shape while you carry it.  The rolled shape also makes transfer of contents between bags really easy. And finally, a good price point - $17 to $24 depending on the size.

What I don't like about it:  Nothing.  It just looks kind of odd and bulky at first but you will appreciate the utility and the literal flexibility of the shell as it molds to the shape of the bag you place it in.

I personally use the Medium and I find this size fits most of the bags I own (... and that is also why this is the only size I carry in my store!  *wink*)  The Purseket does come in 4 sizes - from a drop-in mini insert to an 8 pocket wrap-around for large totes.  There are a number of authorized retailers like me who carry them on eBay and you should easily find a trusted seller from reviewing their feedback.

Beware of the Purseket copycats or fakes...  There is even one seller from Singapore who uses the keyword "Purseket" in his item title yet sells something completely different - One that even has credit card compartments at the sides (huh?)!  I don't think you want ANOTHER wallet in your purse!  Remember that you are searching (actually feeling!) for something in your purse in the dark most of the time!  Unless you carry a flashlight in your purse, you don't want to be taking it inside out to find a specific credit card - so the SIMPLER the design, the better.

You also want to make sure your organizer is RIGID yet FLEXIBLE.  I can't emphasize this enough.  A lot of the pictures you see of other purse organizers are either stuffed to full capacity so that you don't see how the sides become LIMP or collapse inside your purse when one of the pockets or corners become empty!  These are the design details that you don't see from the pictures until you actually use it inside your bag.

You also don't want it to be so STIFF that you can literally see its outline outside your bag - as if you have a box or a book inside your purse!

I highly recommend the Purseket but if you want to try another organizer, imagine how it will FEEL INSIDE and LOOK OUTSIDE your bag when you actually use it.  The pictures usually look really good... but most of them end up looking EXACTLY like they do in the picture - as another organizer on top of your dresser!  8-)   Finally, check the seller's feedback history to see how previous buyers have evaluated the product.