I rented the V6 and immediately noticed the comfortable ride, spacious interior, and well designed exterior. The SRT8 adds power that will push you back in your seat, extremely sporty and comfortable seats, and many options that you wouldn't expect from a sports car. I wanted a sports car but needed a family car. This gave me the look, feel, sound, and performance of a sports car with the room and convinience of a family car.
Pure muscle in the 425 horses. The exterior styling is phenomenal, the interior seating is quite nice. The nav system, dual climate control, heated seats, and bluetooth are great.
I have to be pretty ticky-tack to come up with suggestions, but some of the interior styling could be improved (door panels primarily). Also, don't opt for the dvd player, which adds over $1k to the price. The screen is 7" and not a great value considering portable DVD player options.