The lobby map is the biggest reason I'm avoiding places that are using it, eg. Nordic gather. I myself try to keep my map folder clean from junk and I hate to join a server which is using a lobby map. Also, a normal map gives the players a chance to warm up a bit while waiting for the other players to join. Compared to a proper map the lobby maps are pretty boring. Sadly, however, I guess I'm the only one complaining.
Slow map choosing has never been a real problem in neither of the biggest gathers. Usually picking the map takes only a fraction of the time that it takes for the players to join the server.
As for the stats, I believe there are numerous of possible ways to make the system work without the lobby map.