I also think it's a matter of taste and one is not necessarily better than another. It just depends what people like in their tanks. Many of my friends here have BB tanks.
Sand all the way. I SCUBA dive and the look of the reef is what got me into salt water tanks to begin with. One of these days, I'll see the perfect tank reef while diving, take a picture or video, and recreate in a tank lol!
I think the same way.
I see kind of two schools of thought.
I liken BB to gardening, where folks don't want anything in their systems except what they put there. Like ULNS, where it's a very structured and controlled environment. It's like a vegetable garden in a greenhouse, where you're growing your produce and you don't want anything (including mother nature) interfering with it.
As for the upper reef view, logically, if you're talking upper reef, then there shouldn't be anything on the bottom of your tank, including rock, because rocks on upper reefs are arranged like a wall, not sitting on something. If the rocks are resting on the bottom of the tank, it's hard for me to see that as upper reef? It's just a BB tank.
The DSB school seems to be for folks that are looking for a more natural approach to their systems where they want to try to establish an ecosystem environment with as many of the biomes that exist in nature, replicated in their tanks and allowing mother nature take her course.
For myself I voted DSB and would never consider any other option. I don't like to think of my system as gardening coral unless it would be something set up for a business.