I previously had a HTC Incredible from Verizon. I really liked the phone... when it actually worked. It would occasionally get stuck in a reboot loop and I would have to pull the battery to get it to stop. 3 Times pulling the battery didn't help and it would not let me do a factory reset so I had to get a new phone...
Had it happen again last week (while I was traveling FML) So when I got home I called Verizon and told them I wanted a different phone. I also told them there is a 35+ page thread on the Verizon Forums about lots and lots of people having the same problem.
Basically what they ended up doing for me was giving me a new phone (Incredible 2) but I had to purchase a new battery and back cover for it. (Not really sure why.....). No big deal really since I got the extended battery.
Ive had the phone for about a week now and so far (knock on wood) it seems great. Boots almost instantly and it is pretty snappy. The Camera is a lot better and now it has a front facing camera as well..
boot loops can be caused for varous reasons, but most commonly a corrupt system app, on boot, errors, and forces the phone to try again. I once accidently moved the slider on an overclocking app on my rooted evo up to 1200Mhz(999 default) and it put my phone into an unrecoverable boot loop, i had to boot into recovery and flash a backup, which, luckily, i always keep an up to date one with clockwork recovery, rooted device obviously required.
Having an unrooted android device is like playing an electric guitar without an amp. You should have just spent $50 on an acoustic cort, cause your not getting the full potential out of your android device if it isn't rooted. It's a shame many providers are doing everything they can to keep you from rooting your deivce, damn shame. I have sprint, and it voids your warranty, but that hasn't stopped me from getting warranty work done on my phone, they don't know its rooted if you just reflash a default ROM(operating system) to it when you take it in for work. I had to have the external speaker replaced on my Evo, it took 5 minutes, and the phone never left my sight, the tech did it in front of me. I know other providers are just as bad if not worse than sprint on rooting your device, but they still allow all of the +Root required apps on android market, its awesome.