I just had a long conversation with another forum member on this exact same subject. I had a CCV pop top up until my current SMB pop top, but the CCV was closer to a fixed top with the top down so I feel I can offer a bit on this.
SMB pop top pros: Plenty of light, open and much like a tent with the top up. Plenty of ventilation and
breeze as well.
Lower profile more likely to fit in a garage or clear obstacles/trees and less to think about when driving.
Full walk around height inside when bed stowed to rear or ceiling in newer SMBs, with almost 7' of head room
Easy to store things on roof and access them since top is lower
SMB pop top cons: much less storage
No stealth camping without it being pretty obvious
A little harder to heat and cool. The furnace or air conditioners work well but there is no comparison to a real wall vs. a canvas wall.
Noisier when camping: read above. If you are a light sleeper you will hear more things like neighbors etc. when sleeping up top. This is NOT a concern for most people but a consideration nonetheless.
Anything heavy stored up top (bikes/kayaks/canoe/etc.) usually has to be removed to lift top.
Fixed top pros: Walk around height
Store whatever you want on top if you can get to it
Options for roof air/roof vents if needed
No setup whatsoever
More space inside means more options for layout
More privacy, depending on how many windows
Easier to fit a shower inside
generally better for wet or cold climates due to real walls, easier to insulate
Fixed top cons: increased height makes heavy offroading more challenging, low tree limbs, etc. more likely to get in your way
Harder to park at home for some, won't fit in a standard garage
More to wash and clean
Harder to access roof for storage
If set up with a bed up top, lower clearance for that bed. In other words, harder to get in/out of or climb over someone.
More space to heat and cool
Less windows than a pop top means less light and less breeze.
You don't get to spend as much money on camping, because you can stealth camp. Economy could collapse.