Not gonna draw any conclusions from the lobby I just played with you, since that was very chaotic. Also my viewpoints might be debatable but I wanted to give you feedback since no one else did.
Looking at the map, I think it has potential, but it has big problems with pushes.
Starting with mid: a decent team can easily lock down all the entrances in a 6v6 even ubers situation.
The middle entrances are really small and can be locked down with stickies and spam. The only way to break through is with an ubercharge, or with the fast rollout that you have demonstrated. Both these tactics are not very useful because the defending team has an enormous height advantages. A pocket scout can easily deny any jumpers, and the incoming uber can be spotted very early on by a flank scout looking at left flank, allowing the combo to even retreat to their own sheds which are not spammable by the enemy team, and then repush.
Looking at the right flank: it has a huge sightline with alot of height advantage on the right wall. Only a sniper can counter that sightline, any other classes have no business running to this flank.
Meanwhile the flank scout has a huge sightline looking through the left flank (not visible on this screenshot), being able to see everything besides the right flank. He can spot the enemy combo pushing up and any jumpers doing the fast rollout.
Suggestions: rework the middle entrances so they are more accessible, lower the sheds (and make them more horizontal) to decrease the height advantage, block the sightline from left door into main, and remove the wall on the right flank.
Besides holding middle, basically any forward hold is also very powerful. I think the main area before mid is way too small for team fights. There's a height advantage for the team holding mid, and they can also get behind cover and retreat to mid if the enemy team somehow manages to do more damage.
Suggestions: widen the entire main area before mid, remove the wall on the right side of the screenshot.
As if wiping on mid isn't bad enough, it's even worse if the other team decides to push forward and spawn camp. There's only two spawn doors really close to each other which can easily be stickied by the enemy demo, who can stand on the walkway in the back of the screenshot, and easily get healed by his medic inside the room. Again, if the spawncamping team gets outdamaged they can easily retreat without getting punished because the other team has to push through a small entrance or through a really tiny chokepoint.
Suggestions: maybe make the area wider so the spawn doors can be further apart, give the spawners a small height advantage.
These are just a few basic suggestions, I think more things should be fixed but these are the issues that should be focused on first. I do like the space on mid and the fast rollouts, so try to preserve that.