I just got a Thunderbolt this week, a hand-me-down from someone who upgraded to the Rezound. To say the TBolt runs circles around my Droid 1 is an understatement--I can't believe I lived with all that lag for so long. (Yep, I had that poor li'l phone so loaded up it wasn't funny.)
The TBolt of course is much larger than the Droid, and my buddy sent along the Seidio rubberized case as well. So it is much larger in my hands than the Droid. But...I have long fingers, so it actually fits my hands a lot better with the case than without.
At my last outside sales job, they gave us all RAZR phones, and I hated it--the phone was too narrow and too thin, and I'd actually get hand cramps trying to hold onto the silly thing. You had to hold it by the skinny edges so as not to press the buttons on the inside of the phone, and then you had to be careful as to which edges you held, as some had buttons, making it even more frustrating. I had a bulky but more hand-friendly Nextel i670 as my personal phone and it was a lot more comfortable to work with.
At least this new RAZR is wider, so I would probably be more comfortable with the width than others would. But having held the TBolt both with and without the case, I can say that I prefer holding it with the added extra bulk, and I'm not so afraid of hitting the side buttons inadvertently now.
BTW, not having a removable battery is a huge drawback, especially for those who root their phones or run a lot of stuff on it. How many times have some of us had to pull the battery in order to recover a crashed phone?