I think Stage 1 played out really well, I don't have any complaints about it.
Stage 2, against all odds, was a bit too hard to defend. Seems the only place people wanted to put sentries was on the point itself, and looking around, that seems like the only decent place to put them.
Stage 3 was cramped, really cramped, the connecting passage between cap 1 and 2 needs to be widened a bit. As spy I had trouble getting back towards BLU's forward setup, and just had to hope I was running through there between respawn waves. After getting through, there was nowhere to decloak unless I knew a respawn wave had just come by, in which case I could run around the corner by the first point and come back around, in which case it's most likely a soldier would see me coming up the hallway and start firing rockets...
It looks like you intended that BLU would have a base farther up and the underground-tunnel-thing to the right when coming out of spawn would act like a similar tunnel at Dustbowl's final cap. However, BLU was setting up just around the corner to the right when you come out of that tunnel, so it wasn't actually a flanking route. I wasn't able to play BLU on Stage 3, so I don't know what to suggest, but changes need to be made so BLU can better secure a base farther up that hallway.