I want to know what people hated about BulletMarsh when you take out the fact you can get out of the map.
Without that bug, that map was super tense. Snipers on each side, boom shot in the middle, and a torque on the outside with a great flank path. Such a good flowing map, because there isn't a giant retard spot like Overpass, Sandbar, and Thrashball. (Sit at the top to reap a win)
Bulletmarsh leaves some great CQC in the middle area, and back by the cars where the snipers were. You get that mid range battle for rifles now outside that area, and on the flank path. Then of course, you have that constant threat of the other teams sniper snapping your head off while you try to approach the center. Now without active snipes, it'll be less intimidating and allow only the sickest of shots to strike the fear of the lord in you.
The map aesthetically was super different from the rest of the maps too, because the darkness made you stay more on your toes when traveling the flanking path in case someone was a RAAM hiding in the shadows. This shouldn't be as much of an issue now that every weapon glows.
Plus, who didn't get a kick out of someone going to pick up torque and you shoot out the light so the Kryll maul them and they die? B.Marsh is a great map that keeps battles flowing, and I hope this remains true in Gears 3.