I had an '04 SRT4 for about 40k miles. They're fun cars, and respond well to modifications. The bottom end of the engine will support close to 500 hp stock, and the transmission is pretty bombproof, although it shifts like it is too (ie, don't expect a nice smooth gearbox).
That said, they're Neons with big engines and a turbo. Don't expect high quality from the body/interior etc. Wind whistles at freeway speeds are pretty common, and lots of cheap plastic stuff inside.
I had a Stage 1 chip, throttle body and mopar exhaust on mine, plus a few other little goodies here and there. It put down a little over 250hp at the wheels, and since it was an '04 it had the limited slip front end. I also upgraded all the suspension to Stage 3 coilovers and went with the bigger PT cruiser convertible front sway bar and Neon ACR rear sway bar (26mm front/19mm rear). I wouldn't expect to get 30 MPG's though, unless you manage to drive it without ever getting into the boost. Before modification I think the best I did was about 27 mpg's, after I did some mods it was more like 24 on the freeway, and 18 around town.
The car handled well in the corners for front wheel drive, and when the boost kicked in it went like a freaking rocket. Because of the amount of torque you have to be pretty careful with torque steer, get into the boost while in a corner and the car will happily rip the steering wheel out of your hands and go straight, especially with a limited slip. Back when I was on the SRT forums I heard of more than one noob punching the throttle in a corner and ending up in the ditch when the car just straightened out and took off. Also, even in a straight line with the limited slip the steering will "walk" back and forth as the limited slip does its thing if you put your foot hard into it.
The biggest downside I found, and the reason I ultimately sold the car, is that the vacuum harness is overly complicated. The computer does a very good job of controlling boost and making power, but there are vacuum lines EVERYWHERE. When it was brand new it wasn't an issue, but toward the end I was slowly replacing every vacuum line on the car to maintain boost/power. The plastic lines would crack, the rubber boots at the ends would tear, etc, etc. The dealerships will be of little help in this area, especially now since the car only had a 3 year run.
And the tuner crowd was annoying after awhile. I got tired of being profiled as a street racer and ricer too. Keep in mind too that it will probably be hard to find a car that hasn't been beaten up by its previous owners.
Still, I liked the car for the most part. It was a lot of fun, and would kick the *** of just about anything even close to being in the same class at the time. If you're good with turbos it'd be a good car to play with. I sold mine after I bought my Challenger, just not a new car guy.
My car in its heyday...