I bought three of them new....a '79 with a 1.7, an '82 with a 2.2, and an '87 with a 2.2. All were automatics..non A/C... and I never had a serious mechanical problem, although the VW-based 1.7 began to burn oil at 70K. It also need front hub bearings at 50K. I replaced the struts on the '82 at about 100K.
All averaged 30-36 mpg in normal driving. The only recurring problems were outside door handles that stuck and broke. Later models had heavier parts, but they still had problems. Manual transmissions had linkage problems, but Mopar developed improved replacement parts for retrofit.
As far as performance, they were competitive with other 4-bangers of the era. The '87 was the only one I ever took to the track, and it ran 17s...about the same as a slant six in an A-body.
They were especially easy on tires. The OEM Goodyears on the '82 lasted over 90K. All got more than 60K from the OEM tires.
The 2.2 was a great engine, and mine never developed head gasket problems. My daughter drove the '82 for nearly 200,000 miles and it still ran well without burning oil, but the body did begin to give out at that mileage. I never had to do anything to the automatics. I never added a drop of fluid, and never changed fluid or filter.
I never had to replace one, but the Mikuni carburetors were very expensive. I rebuilt the one on the '87 myself, and never had a problem after that.
All in all, I was very happy with them. They were fun and inexpensive to drive and the last two had extremely comfortable seats, though they could have used tilt steering. I would have bought another if they hadn't stopped making them, so I went with a Sundance 2.5, auto, that also proved to be a great car.