I had an '07 Jeep SRT that was fully optioned out (reverse camera, nav, sunroof, etc.). I regret to this day that I no longer have it; it was $ for $ the most fun car to drive that I've ever had.
With that being said, it was not without its problems...
The '06s (first model year) had their share of electrical gremlins and my '07 wasn't much better. I had a control module replaced twice 'cause my dashboard was lighting up like a Christmas tree and it was still quirky; windows wouldn't always go down, etc.
I'm 6 foot/200 pounds and the interior (at least in the front, I've never sat in the back of one of my own cars) was sized nicely, although it might be a little cramped for someone larger. The seats are fully bolstered and very supportive.
The gas mileage was horrible, period. I didn't care 'cause I knew what I was getting myself into, but on a Kansas-flat highway @ 65 MPH with 90 year old grandmas giving me the bird and trying to run me off the road I could not get over 16 MPG. My mixed mileage was a constant 12.5 MPG, sometimes launching like a complete idiot, sometimes driving like I had a bald eagle egg under the gas pedal. The tank is small too, but that's typical of SRTs.
If you're even considering using it as a tow vehicle, don't. The factory hitch looks like ass, doesn't work with some aftermarket exhausts and is only a 1 1/4 and only good for 3500 pounds. The weight limit is due to the tranny's capabilities and it would surely tow more, but if you want to stay within the manufacturer's limits you're, well, kinda limited. The Trailblazer SS is a good alternative and has a decent rating (6600 pounds with AWD) but can't come close to running with a Jeep SRT without some modding...
The run flats are GAWD awful, especially on the fine New England roads that I'm honored to drive on around here. Swapping out to non-run flats and picking up a SRT-8 tire repair kit is a very common and highly recommended "mod".
If you test drive a Jeep SRT, you're screwed. You're not going to leave the dealership without it, it's that much fun.
Good luck with your decision...