I'm still on the fence.
For the Thunderbolt, the reported reboot issues are a deal-breaker for me -- reliability is my number one consideration. The reported battery life is also major concern, though I'm willing to buy an extended battery if that will let me regularly at least 18 hours on 1 charge with 6-8 hours of local music playing and 1-3 hours of LTE web browsing. I'm willing to install an AOSP-based ROM (CyanogenMod 7, which I use on my Droid, would be my preference, but it isn't even at alpha yet) if that solves problems that the stock ROM has without losing key capabilities.
For the Charge, I'm a little worried about it only having 512MB RAM (vs. 768 for the Thunderbolt and 256 for the Droid I have now). I'm also a bit worried about reported lag with the stock ROM, but I'm willing to try the Voodoo lagfix that reportedly addresses that, plus I'd probably use ADW launcher (like I do now) in place of the stock launcher. The Super Amoled screen is a plus,and reports that it is much easier to read in bright sunlight than the Thunderbolt's screen is also a plus.
I was regretting my TBolt purchase for about a month. I was thinking, two year contract for this???
Then I rooted. MR2 fixed all reliability concerns. And I had random reboot BAD.
Then I installed CM7, Now in Alpha. With CM7, it can be used as a DAILY DRIVER and it makes this phone as smooth as an iPhone as far as lag is concerned. OH my goodness, CM7 makes a HUGE difference. And really, some say it's boring compared to stock. I diasgree 100% on that. It is very clean and gives you enough tweaking ability along with a custom launcher. I even had the Sense 3.0 preview installed with the fancy stuff. Give me AOSP! There are a couple MINOR issues with CM7 (more so if you live in a 4G area with the handoff--but you still CAN use 4G on CM7! Don't worry about that).
So anyway, I am a happy camper and this is the phone I will stick with. Not even concerned about Dual Core or the "next big thing".
One more note, An Extended Battery is a must. I don't have to charge all day, even if I am on 4G. CM7 is supposed to make battery life better on top of that. As far as the weight and size of the extended battery, after a day, you will be used to it. After two days, you might even prefer it!