Bought the car for $1000 as a commuter for my girlfriend. It had been a city car most of its life and had scars to show (little dings, curbed rims).
As soon as we got it we did a basic tune up with plugs, wires, filters and an oil change. There was a noticeable difference after just doing this. It took a few oil changes and a lot of proper non-stop-and-go driving before the oil seemed to stay clean for more than 100kms. Now by the time a change is due, the oil is more gold than black. Like any car, regular maintenance is your best friend.
For its meager power it moves around pretty good, partially due to the Festivas very low weight. The only time it really struggles is on steep hill/mountains, and even then as long as you're patient you'll make it up at a decent speed. We've got the three speed auto, but I would strongly recommend the four or five speed standard just for better mileage and a lower highway RPM.
The car is great for the winter; with skinny little snow tires or all seasons, you'd be surprised at what you can plow through with ease. Your only limiting factor is clearance; you have to have enough speed to make it through the deeper sections, or the front end of the car will get lifted up and you won't have any traction at all. The car does have a block heater, but we have yet to use it.
The car has been very reliable and never left us stranded once. It has always started no matter what the temperature or how long it has sat.
For a small car it is very comfortable, has surprising amounts of room, and a unusually soft ride make for a decent drive.
It has been a very economical car to run; any parts we have ever needed have been reasonably priced, and it's great mileage is always nice.