I think the idea is that if you swivel, you don't need to pull the chair out (and in) to sit at the table - you swivel so your lap isn't under the table and get up. And yes, it's harder to slide swivel chairs.

Thinking of getting new patio dining set. I know the kids will be fighting to have swivel chairs. If I get a set with all swivel chairs -- will it be hard to move in and out b/c of the circular swivel base? I mean -- do these types of chairs slide well when you want to pull up to the table or slide away?

Or is there some advantage to having a traditional four-leg chair?