Our single super slide has had just one repair in its 17 year life. Last year I had to replace the operating switch that was getting hard to make contact. That took about 15 minutes and cost about $12. This year I'm replacing the slide topper fabric that's starting to look its age.
There are a number of slide floor plans that allow pretty good access with the slide in, but not all do. In our case, the only thing we lose, besides the obvious floor space, is access to a single little used 120v outlet and a wall mounted picture is hidden from view.