Have we tried this?
cs_siege_source
This is the best attempt at recreating the famous map from counter-strike that I have seen so far. The overall layout is the same, but a few things have been changed. The spawning area for the terrorists is simpler, and the hostages are harder to camp. The water pipe system is darker, and the entry ways up to the car garage are modified. The car garage itself is different. My favorite camping/sniping spot that was near the door leading to the sewers is gone, and the cars have been rearranged. The building that lies in the middle of the two spawns, has a much more detailed interior, but the mobile home across from it is now gone, replaced by a shipping container. Playabilitywise, I really can't comment on because I couldn't test this with 20+ people, so thats a question that will have to be answered at anothet time.