OK,

First of all, the John Deere L100, or 100 Series tractors are not Industrial Mowers.  They are sold at John Deere Dealers as well as Home Depot and Lowes.  If you have a reasonably smooth lawn and you are cutting normal lawn grass or maybe blowing some snow in the winter as well, these lawn tractors will do just fine.  I have the L118 from when it first came out in 2004 and have about 180 Hours on my unit.  It mows grass in the spring, summer and fall and then blows snow in the winter.

These units are not field mowers by any stretch, but I have used mine to rim around the edges of my 5 acre property in less than ideal conditions.  Expect to go through a set of belts every 150 hours.  Other failures I have encountered is the failure of the deck spindles, 1 pully, 1 battery, and 1 starter solenoid.  Total parts cost was under $150 and I did the labor myself.  I don't count Belts, Blades, Air and Oil filters, or Engine oil as those are normal maintenance items.  

These units are as good as anything you can buy at Sears and you get the advantage of being able to get parts at the local John Deere Dealer or at Home Depot/Lowes.  For the most part mine has given everything I expected from the unit for the price I paid.