So, I may have a bit of a unique perspective on this one. I currently own a 2003 SRT4 and a 2005 SRT6. I just traded in a 2005 NA Crossfire about 4 days ago.

I have raced them all against each other. As for SRT4, mostly stock with just the predator tune, vs. NA Crossfire with Eurocharged tune; the 0-60 is the most similar. The SRT4 starts to really walk away at 60 to 90. Never really raced them above that.

Now, the SRT6 is just nasty stock. It walks away from the SRT4 after sixty. But rolling from 20 they are pretty similar. Out of the hole, the SRT6, I suspect will destroy the SRT4. I will race them soon with one of my bodied that can drive.

That said, I love(ed) all of them. The SRT cars clearly had passionate engineers. I would disagree that the interior sucks on the SRT4. I think it was an inexpensive car that heavily engineered for speed/performance and the passion involved in its engineering is quite amazing but takes a little time spent with it to truly appreciate.

The SRT6 is the best car I have ever owned. It's not overly nice interior wise, but overall the package is amazing. I hate to say it, but I wish I would have traded my NA Crossfire long ago :-)