I'm telling you, these things are going to take over. It seems like every week people are asking about them, and for good reason. They are cheap, and sound great.
I have a QRX-6500, and I just sold a QR-6500 on flebay.
I've never had a problem with either, other than the tuner string usually slips on these models. Re-stringing the tuner would be an absolute nightmare, so cleaning the string and tuning knob is the easier fix.
For the money, they are awesome. And yes, they are very reliable.