bb_research_facility has a huge problem with causing excessive video card lag. I don't know if there are too many entities or whatever, but when I look towards the center of the building, my framerate drops from 99.9 to below 10.
I'd have to agree on this one. It's not very straightforward and sometimes the server gets stuck until someone who knows the map joins. This map should be taken out of the rotation if it hasn't already.