First of all, welcome to the forum! I hope you stick around and become a regular poster and OCer.
I have a GLOCK 22 and I love it. GLOCKs are very sturdy and reliable, so as long as it's in good condition you should have no problems with it being used. Just make sure to field strip it and take a look at the condition before you buy. As for the GLOCK warranty, they will fix pretty much anything whether you're the first owner or the 20th. I've heard many good things about the company in those respects.