So i'm not sure i like the final point. You say you've changed the catwalks, so odds are you've fixed this, but when attacking C i felt like either i could attack through the lower area, and just get sniped or outranged through the big doorways, or, once i'd found my way up, end up in a small space where either i'd be killed by the sentry opposite, or the waves of defenders coming through the upper spawn.
I guess you're kinda going for a "Gorge" feel at last, and two things that are cool about gorge's upper route are:
1) The lower and upper route go through the same space. You can take the upper route and then drop down into the lower, or use it as a way to block counterattacks. On Hella, it's an entirely seperate corridor. Get attacked in there, you're miles from the rest of your team. It's a lot easier for a single rocket-jumper to push players back.
2) The attacker's area on Gorge is really big. There's plenty of room to move about there, and you have the advantage over the defender's raised positions, meaning even good defensive positions can only really cover the point and lower entrances.