I picked up a Ridgid 6" a few years back to scuff sand the hardwood floors of a rental house.
They were in decent shape and didn't need sanded all the way down to bare wood.
I've since used it on smaller tasks.
The other sander I have is a DeWalt 5" single speed. I like to use the 5" because it's nimbler and doesn't seem to add that much time. The DeWalt is near its end of life however and I'm looking at what I can replace it with.