I just test drove a 500 today. I thought the fit and finish was pretty solid overall. The interior was a lot nicer than I had expected and the whole car felt like it was put together well. Plenty of interior space and decent enough room in the trunk. I thought the handling was decent as well. I do have a few complaints though:
1) The seating position. I could not get comfortable at all. I felt like I was sitting up too high and my right leg was pressed up against the console the whole time. My 6'5" friend seemed to fit comfortably in the passenger seat though.
2) The clutch and shifter felt really really bad. The clutch pedal was just really squishy and I wasn't able to drive the car smoothly at all. The shifter was amongst the worst I've ever used. Really vague and rubbery.
3) It was slower than expected. I guess I've been spoiled after driving a 500+ hp car for a while, but I'm not used to downshifting to get up small hills.
Other than that I really did like the car. I'm curious to see how they hold up in the long run and maybe I'll give it another shot when the Abarth comes out.