Yes Lean Bear, I see what you mean, I feared that the lack of such maps with the enterable buildings can be related with the lag problem.
That's a shame, because I have some great ideas for the missions on such map. Not a long ago I've watched an excellent WW2 documentary "The battle for Aachen". Now what a carnage that was! Firstly there were a street fightings, then house to house fightings, then floor to floor, then room to room. I know (as does all the sane people) that war sucks and that is a brutal thing, but after that documentary I was in shock!
Well, I'll survive if no such map will come out in the future; there's plenty other maps out there to play with.