I've only owned my 2014 since November, so I can't comment on long-term reliability beyond what I've read. However, I have yet to hear about a major problem with these cars, even the older ones.
What I can tell you is to not even bother with a Rio or Yaris. As deadlydave said, there's a difference between cheap and inexpensive cars, and those two are cheap garbage. The Fit is the only close competition for the 2 in the segment, if you ask me. I was personally not interested in one because they're considerably overpriced by comparison and not any better of a car than the 2. The looks don't really do it for me, either. Being a loyal Mazda enthusiast, the 2 was really a no-brainer. It's got everything you need and nothing you don't want.
Seeing as how the Fit is out of your budget anyway, the 2 is a smart choice.