What do you want to do with it?
If you're a vagabond that wants to sleep on the streets of major cities then smaller is better.
If you're insistent on avoiding any campground at all costs then smaller is better.
If you're insistent on being an off road warrior, smaller is generally better.
If you're the kind of camper that continually is in and out of state parks, smaller is probably better.
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Aside from being an outlier above, in general, floor plan is by far the most important thing. We've been in 26ft TT, 43ft DP and a 45ft Fifth wheel, never had a size issue. I think in 10 years out FT we had one or two instances where the park we wanted to stay at couldn't fit us. That includes state parks. In every case there were other parks more or less a mile or two away that fit the bill.
So size was never an issue for us. We aren't allergic to commercial campgrounds and we do our boon docking while traveling like the rest of the RV folk. No issues.
