The reason the first round is so long and/or results in a stalemate is because of where the point is when compared to where the enemies come into the zone. One of the entrances is right by the point, another is below the point, the other far away and out of immediate line of sight. It is also easier to defend this point because of where barriers (props or displacement pile things) are.
The reason the second round is so quick (that is, the team that has advanced gets their point capped fast) is also because of where the point is when compared to where the enemies come into the zone. Two exits have the point right in clear view - the 'empty' side of the point. One exit is beneath the point, the other is far away. The former and latter makes it simple to take out sentries and people from range. Sentries already have a tough time. It's as if you built the middle points for only that middle, first round - all natural defenses are on that side of the point. [I cannot give help on the team that has been pushed back, and on their point. I have not lost enough and played defending on that point to give good criticism.]
The last point is half-good. The defending team's side is great. Point's on a hill, being overlooked by a tower, it's all good. But attacking team's entrance isn't. I said it in the chat when you weren't there/paying attention: "Last round is okay if you take out the door game part (where the host tells you there is a prize behind one of the three doors, and no matter which door you choose, you die)." Essentially, the attacking team leaves spawn, walks to the building, chooses a door, goes through it, and dies.
So essentially, the second round needs work, and the middle points need some natural defenses on both sides. The third round is alright, but too defender-friendly. And may I suggest thinking about reducing sentry count on round 1?
Here are some screenies of things I've noticed. Most are actually from a2, but I've still noticed a couple in a5, but I apologize if you fixed it already.
http://dl.dropbox.com/u/1490725/tc_faultline_a20000.jpg
Fence is off the ground.
http://dl.dropbox.com/u/1490725/tc_faultline_a20001.jpg
Unsewn/Faulty Displacement
http://dl.dropbox.com/u/1490725/tc_faultline_a20003.jpg
I'm weird and use the windows above as a sentry spot (it covers the point, but soldiers/snipers from across the point can take it out easily) and snipers should use this, but c'mon - I rarely see anyone in there. Give us a reason to want to use that place for defense - maybe a small health kit/ammo pak, or just some form of usefulness.
http://dl.dropbox.com/u/1490725/tc_faultline_a20004.jpg
In that same place before the ramp to the windows.
http://dl.dropbox.com/u/1490725/tc_faultline_a20005.jpg
I think you fixed that, but not 100% sure. Shiny Truck!
http://dl.dropbox.com/u/1490725/tc_faultline_a30000.jpg
http://dl.dropbox.com/u/1490725/tc_faultline_a30001.jpg
View distances, or something
http://dl.dropbox.com/u/1490725/tc_faultline_a50000.jpg
Unsewn/Faulty Displacement