My friend just bought one...black and R/T trim. Although I would get the challenger over the new '10 Camaro, I wouldn't get it over the '10 mustang. To me the mustang is more refined (lol can't believe i just said that about an American-made car)and nicer looking.
For one thing... the challenger does have the American muscle personality. It's a big V8 and it's loud in the low RPM range. (like you said) Sounds REALLY aggressive and loud which is what I like. Design is really nice from the front (almost scary looking) and back...has the older generation Challenger look to it.
The challenger is way too big though..and very heavy. Even though it has 380hp 5.7L Hemi V8 engine...it's not enough to pull the heavy thing. The E92 M3 has a broader RPM range, more hp, and lighter while the Challenger R/T has less hp, heavier, and a lower RPM range than the M. Only advantage that the Challenger has the torque...but that's it. You would wreck.
..wow this is the most i've ever written in one post..........