As with any big decision there are multiple reasons;
- We love going to smaller, less crowded locations.
- Tight roads, trail heads, camp grounds... (every hear of the 'Going to the Sun' highway in Glacier NP?)
- Costs, both new and operating
- Ease of driving
- Fear of backing up (hers not mine, I drove school buses for a couple or years.)
We had a 23' class C (overall near 30, no slides) for a few years. We took it up the Al-Can highway with the then kids for a month. We all fit in that well, so just us 2 should be great in a 30ish rig. We don't want a King bed, sofa & recliners & dinette, 2 baths, 3 TVs, etc. Some kitchen counter space and a moderate shower are on our list.
Some of the 25's do look a bit small and a week in a 30 was great. I can't promise that once we really retire we won't want more storage. I've also been starting to think that we have been focusing on camping, but there is also a 'portable hotel room' side to this.