Since I just got this car, I'm not sure of the problems the previous owner received, but here's some that I ran into.
Approx. 120,000 - Engine gave out due to negligence. I knew it needed service, but didn't bother fixing it. It was completely rebuilt. I also beefed up the horsepower a little bit with better engine parts, intake, filter, etc. for some extra good fun - Cost approx. $400 from good mechanic buddies.
125,000 miles - The little knob that controls the headlights, turn signals and high beams popped out. Headlight switch still had power, but I was unable to switch it up and down for the turn signals. Brand new, and premium quality replacement parts from Mitsubishi have been installed. Cost - $114.
Recently - engine "tapping" noises have began showing up. It's probably the cylinder heads needing re-alignment due to the recent rebuilt. Car kind of sounds like it's diesel powered now, hehe. Doesn't effect anything, other than its dignity.
Overall, the reliability is stunning. The car does its job with minimal problems, and then some.
Very quick, thanks to it's light weight (around 2600 pounds) and FWD-Manual duo. Burns rubber like no other, accelerates off the line with fury and tops out at insanely fast speeds for a car of its type. Sporty down-shifts are responded by a burst of acceleration, especially on 2nd gear, which tops out well over 50MPH.
Handling on the other hand is poor due to its height. Grips the road nicely, but has high levels of body lean, even at low-speed turns.
Interior noise is mind boggling. My car in particular has lots of loose parts causing all sorts of rattling, but in general, Summits tend to have lots of tire rumble, wind rush, engine roar and what not, especially at freeway speeds.
Very roomy interior with comfy seats. Lots of leg/head/elbow/breathing room in both the front and back seats and to top that off, there is an abundance of cargo space in the trunk. With the rear seats fully folded, I was able to fit a fridge in this little van.
If adult-driven, this car gets around 25-30 mpg. Small tank would fill up from empty to full with about $30 ($2.44/gallon) and it can go around 300 miles on that. Very useful, especially with todays gas prices.
Overall, this is the best car I've ever owned. A real treasure if you ask me. It's got everything you need in a car (superb performance, comfort, roominess, gas mileage and reliability) with the exception of quietness and eye-candy.