Personally, I'll probably go for the R/T when it comes out. The V6 will NOT be available with stick, and I want that. I currently own an SRT-8 Charger. More power than I really need for sitting in traffic on the way to work. I think the R/T will have plenty of power, especially since it will have 30 more horses than the current Charger R/T.
BTW this article says the V6 will get 18/25 MPG. That isn't very impressive. I get 16/23 with my SRT-8 Charger. Not much better on the gas, although you can use 87 octane with the V6 and 89 with the 5.7, where I have to use 91.