I'm sure you are right about that... but there would still be framerate issues like in Reach with Forge. A lot of really good big aesthetic maps have framerate issues. It's just not a problem if it's an aesthetic map just for looks.
I'm thinking about going as extreme as re-making the entire map on top of the smaller asteroid to use the natural terrain as a floor and on top of that I won't have to worry about putting as much "railing" around the map. It would change a lot but probably for the better. I would still use all the same buildings and same concept, but the highway would have to run right down the center of that asteroid, so it would be at a pretty steady incline, giving the city a San Francisco feel. Man, why do my updates require so much damn work...
haha...that's why I pretty much give up on all my maps. I think a good map can take a month or two after testing...crazy. That would really suck redoing the whole thing though. I'd still try to fix the framerate before doing that... there has to be a good way of doing it and keeping the map not much different.