I have to disagree with this point. I see the performance boost as being negligible unless the map is ridiculously massive and everything were built out of BSP which it never should be anyway. As for speed of workflow, it just comes down to preference I guess. For example, I find it faster to cut windows and door frames by simply placing additive and subtractive BSP’s together than to model a wall in another program (maintaining quads) fiddling with the poly’s to make a hole, applying UV/Unwraps to it, then exporting and importing it into UE. Not only that, but if you needed to move that window or doorway a few units to the left let’s say, you’d have to go through much of that process again whereas doing it in BSP, you would simply move it to where you needed it and be able to test it right away.
Sure but that mainly applies towards meshes that should be repeated such as cars, foliage and any other meshes that would benefit from this. If you have the interior of a building as a play area (I mean walls/floors etc, not decorations) it wouldn’t really be instanced elsewhere in the map unless you’ve constructed the hallways/floors and such as modular pieces. I find that the modular method opens you up to a slew of problems with lighting/shadows/alignment and flexibility that could have otherwise been avoided with BSP.
I guess at the end of the day it all boils down to what feels more natural to you but don’t be scared of BSP for your floorplans.