I too had an SR4 from JT, I had it about a week and was firing it in my backyard when the thing took a dump and wouldn't feed, making this strange sound when I pulle dthe trigger. I got kinda angry, I had just spent like $250 on my first rifle and this?! I took it to JT, not even the one I bought it from, actually, to see if they could tell me what was wrong and what I could do to fix it. Long story short, without ANY problems, I walked out of the store with a brand new one, and an extra hicap. On another occassion I had a crappy KJW M9 mag, I went to JT to ask what the problem was, they exchanged it for a new one.
What I'm trying to say here is that I have absolutely nothing but the best experiences with JT, especially the stores in phoenix and scottsdale. And that's why I'll spend my money there happily.