What I find rather interesting is how there is no "perfect" area on the second bit of the map. The Reds have a massive viewpoint advantage, and sentries will be able to overlook a majority of the area, but no one sentry would be able to cover all the map. There is still a few nooks for a demo to launch grenades from. I hope you don't mind, but I edited your picture to give a clearer idea of what I mean:
The closer the reds stay to their base, the better control they have over their territory. From near their base, they have got the blues in two separate choke points, but if the start to go towards the middle ground, they start to lose that advantage, as snipers could easily take them out from the Blu base as it has a straight line of sight towards that lower ground. Very interesting, and it seems very balanced for a draft diagram.
On the flip side the Blu then have only limited entrances and neither of those provide viewpoints which directly open up onto the Red base (was this intentional?) meaning a sneaking Sniper can't just spawn kill, as he could never get a clear shot to the base.
The Blu team will always have to keep moving forward, and setting up new defensive lines as the cart moves forward as the terrain means long range combat isn't possible, and the Blu need to keep on a constant offensive.
Very nice, very very nice.