I didn't buy one, but looked into it. I was shopping for a 60hp. They had two groups, ones that had super low hours (100 or less) that they would only sell with boat packages, and ones with high hours. If you walked in and wanted a motor separate, you could only get ones with 500 hours on them. To me, the discount off retail didn't seem enough for using up the best quarter of their operating life.
I heard mixed info on how abused the motors may have been. If they are client driven, I assume it's equivalent to a rental car, pin it and go, no worries. But I met a guide from the charlottes who said they actually took really good care of the motors -- he got in trouble, because they reviewed the engine stats every few weeks and found out he was back trolling with his main motor instead of the kicker. Too many hours at that RPM would violate their agreement for lease returns.
Maybe there's part of the answer...for motors with a history that can be reviewed in the computer, you can be assured it has been well taken care of. The others, buyer beware!
Prices are tempting though.
And keep an eye on Seattle craigslist, I've seen some good deals on kickers down there.