We like our 24, which is really 25' long. Easy to park and all sites we've visited, including state and federal fit well.
We have a 2003 Chevy Tracker that we tow 4 down on occasion for when we don't want to unhook to visit local sites at our destination. Even if we don't, finding parking is easy unless it is in some major downtown area.
One nice thing about being bigger than 24 is it can offer a walk around bed in the back. (Some still will offer that with a side. That is admittedly tempting.
History: '08 View, '05 Chinook, '01 Jamboree 24D, '78 Apache Popup, 81 Komfort Tlr,
84 Mazda B2000 'w canopy,
Tent from wedding shower in '96