I agree with above. SMB pop tops definitely add value and are never hard to sell, either the whole van or the top alone but those come up very rarely.
Where you are located and where you travel matters a LOT. If you're in the eastern U.S. and travel there and maybe go to Florida now and then I wouldn't recommend a pop top. I'd get a fixed roof with powerful shore power air conditioning.
If in the western U.S. where it's cool at night and rarely humid a pop top is an excellent idea.
Lots of rain, say the PNW? I'd go fixed top. Just like REF said, it's a loaded question.
Then there is parking. Many people with HOA's or low garages like pop top vans.
Good luck in your search. Lots and lots of great info and helpful folks here.