Played this again last night.
My only gripe with this map is, still, the last point of the last stage. Everything else seems to play out smoothly, but that one point is too easy too camp, too difficult to attack and generally degenerates into a sheer battle of attrition.
The reason is simple: After that first part with the side routes the "finale" is basically one long and wide hallway with two long and wide side corridors where the red team spawns... This makes it incredibly easy to camp by way of "sentries right off the spawn" coupled with "spam down the aisle". Red team then has to break through the initial defense, outright GRIND all the way up to the junction, THEN destroy red's sentries (usually on both sides if red is an half-decent team), conveniently located right in front of their spawns and finally score.
The only times I remember seeing blu win this final stage was either: a) Massively coordinated uber rush with red not putting that much of a fight, and b) When blu is steamrolling anyways.
To me this is the only significant problem with this map right now. Suggestions to fix it? Well, maybe a simple glass "frame" in the middle of the aisle (think you had that at some point) so blu has some room to move up a bit without being pelted by snipers, heavies, soldiers and demos. Red would retain visibility of it's enemies, but blu would gain a little "buffer" area to make that final push.
That's pretty much it, the rest of the map feels pretty solid to me right now.