Advice on Folding Bicycle
A good folding bike should ride just as well and last just long as a traditional bike. BikeFriday has a reputation for bikes that feel "normal."

As far as maintenance goes there is very little difference. From my experience the only thing that needs more frequent maintenance are the cable housings. This is because cables usually have to make more complex cable bends on a compact folding frame. This causes the housing wear out a bit faster. From my experience about 33% faster than my traditional bikes.