The 10/22 is a solid design, there's a reason it's been in production for over half a century. It's as American as apple pie, and I would put it on par with the AR15/1911.
I got 3x 10/22's all of which are modified in some form or another. 2 of the 3 are flawless and eats ANY ammo, the last one has an extractor issue ($15 aftermarket fix). Like any product you take your chances with their QC department, and as of late it seems that Ruger is more focused on pushing out new products than to maintain QC.
If you don't plan to get into the aftermarket game, stay away from the 10/22. On the upper end of things I'll recommend the Canadian made Dlask DAR-22/TUF-22, and on the lower end I hear good things about the Remington 597.
Friend of mine has the GSG-15, and if you want a rifle that eats ANY ammo...don't buy. GSG-15 cannot cycle subsonic ammo or Winchester Bulk. Oh yea...and there's an issue with light primer strikes. As for the KEL-TEC, the main issue I hear about is the customer service and availability.
Hope that helps.