Well, I now own both, so here you go! These are two completely different cars. It depends on what you will use them for. The SRT-8, as someone stated, is the best bang for the buck. You can't find the balance of sheer power, amenities, and looks on any other sports sedan for around $42k. You get a daily driver and also a car that, despite what some people don't know, is an amazing car on the track for it's size and weight. Some of the amenities are backup assist, full screen NAV, satellite radio, automated windshield wipers, Xenon lights, telescopic steer wheel, auto headlights, Uconnect bluetooth speaker, etc.

The downside is the gas mileage. But, hey, you're not getting the car with a 6.1L monster engine to get Prius mileage! I test drove many luxury sedans and I kept coming back to the SRT-8. I actually was putting a deposit on a '05 BMW M5 and decided that it wasn't worth about $15k more.

I bought the SRT-6 because I wanted to keep the miles off my 300 and also wanted a fun 2-seater for the track and cruising. If you are into modding, the 300 has a lot of vendors to help take the car to whatever level you want to go. One particular vendor is Diablo. Someone has finally been able to produce a tuner for the HEMI engines. From what I've seen, you can get 20hp+ right out of the box. Also, you don't see alot of 300C SRT-8's around. Maybe the regular C. If you want a 4 door luxury sedan with lots of power, go with the 8. If not, the SRT-6 is a blast to drive - just without all the amenities.