24 is a great size. For me, I don't really want to handle larger pieces of vinyl anyways.
I used to think "man these 24" rolls are HUGE" when we started. We were only buying 15" rolls for our 24" machine (big bucks for the 15" rolls when you start!).
The other day I found a 15" box next to 54" media. I nearly broke my head from rolling around on the floor laughing at the tiny size of it.