I've had a couple of Bolts and a couple of Inc2's. From a standpoint of the experience and the OS, they're 99% the same and have the same feel.
I agree with Coltrane that the Inc2 is better as a phone, but the Bolt is good too. The Inc2 is the best actual phone I've had in a long time, so saying it's better than the Bolt is by no means saying the Bolt is bad - the Bolt is great as a phone as well.
Battery life sucks on the Bolt if you use it, especially on 4G, you'll be lucky to get 24 hours... on 4G the whole time, lucky to get 16 hours. The Inc2 has great battery life - 24+ hours easy. I've gone 48 (on extremely light use and on wifi, but still) and had 20% remaining.
The Bolt can do talk/data at the same time on 3G alone b/c of its SVDO chip. It's the only phone on Verizon that can do this right now, on 3G. Obviously any phone on 4G can do voice/data at the same time b/c of the different methods of transmission.
Any 4G phone is going to be larger/thicker b/c of the radio - so that depends on how much you're willing to sacrifice there. I will say the Bolt has good form factor - so despite it's thickness, it's still very "pocketable".
I've had zero gps/location issues, as opposed to Coltrane, and don't think it's a widespread problem based on what I've read and my experience with various phones. The Bolt had a ton of issues early on, most of which have been fixed now - so it's good you're not an early adopter of that phone.
I've stuck with the Inc2. For me, battery life is more important than super fast speeds, and the smaller size is more important. But that's what I want... you have to prioritize what's important and what's not
for you.