When I got my first TBolt upon it's release, that phone was a nightmare of problems. Every problem you could have, I had. But I ruined my display by talking on the phone during a hot day and sweating through it. I paid $99 for an insurance claim and was lucky enough to get a brand NEW phone, not a CLNR (trust me, it was brand new shockingly enough). Since the new phone, I've not had any problems at all. No rebooting, nothing. I may occasionally lose my 3G service after a bad hand off between towers, but rarely. A battery pull fixes it. But it's very very rare. I think that for whatever reason, the first shipment of these phones had the same problems that that manifested themselves in different ways for each user. But the overall problems were the same. But I believe that somewhere down the line in production, something changed and the phones started to not have the problems, whether HTC or VZW would admit to it or not. I'm betting that thousands upon thousands of "bad" phones went out originally. But nothing was ever said about a problem. And my replacement phone that showed up had the same firmware, etc. So I think it was a component issue, but who knows.
I just know that is at one time, I hated this Thunderbolt so much that I wanted to smash it. But those memories are long gone and I can say that I'm very pleased with the phone. There are some minor gripes, but nothing major.
I think it's hit and miss w/the Tbolt, but I 'd say overall, it's a solid device. I'm sure the CLNR's floating around are problematic too.
j