First off welcome to forgehub. =) Second I like the ceiling but to me asylum is a open map and closing it in kills the feel of the map. It could use a little light. My suggestion delete some of the roof and let good ol' sunlight in. But besides that solid remake. Look forward to seeing more.
You do know you don't have one piece of light shining through anywhere? you can't make huge closed in maps like this anymore... unless you break the dynamic lighting on purpose. Halo 4 is a bit different for forging maps. I would delete that ceiling and use window coliseums or something (for light). Otherwise, it just doesn't look very appealing at all and will turn a lot of people off from even wanting to play on it. That's my opinion anyhow. It's ok if half your map is shadowed with the poop brown but at least the other half needs light to differentiate where you are on the map if anything, as well as so the map looks good. Everything just blends together otherwise, and has a very "artificial" look.