I had Republic for over a year but once my job offered to pick up my cell phone bill i switched to Verizon. (if they hadn't though I would have gone to another MVNO)
Overall the Republic phone (MotoX) was fine, but the call quality was pretty bad. I can't count how many times I had dropped calls, or people on the line saying they couldn't hear me, or the bizarre problem of not being able to log onto conference calls sometimes. I also live right in the middle of an urban area, so it wasn't a lack of service or anything like that.
My wife still has her Republic phone, but rarely talks on it, so its fine. But since I do a lot of work related stuff on my phone (I also work from home)via 1:1 calls and conference calls, I just needed something that was more reliable. So I guess if you talk on the phone a lot, I wouldn't necessarily discount how important call quality and reliability is. I did and after a year I had to get something better.