Well. Where do I start.
This map was not even close to hard compared to the level of annoying stuff that's in here.
It seems that in order to solve this map you need to use the glitchy nature of this tile-set.
There are small edges everywhere that you need to balance on.
When this is a requirement, the focus of the map shifts from "thinking with portals" to "where can i jump".
Exampel: in the bottom room you clearly intended that the solution was to use momentum to get up a cliff. but i only noticed that some time AFTER that i jumped on small edges across the room to the other side. (We actually never used the momentum thing)
I think the puzzle would benefit greatly if you cleaned it up and used the standard tile-set. Then it would be a lot clearer where you could stand and not, where you can place a portal and not, and so forth.

Because you got some stuff there that's really good! I really liked the way you had to go between the top and lower room and place portals to transport your comrade, search for angles to get the laser right on target.
Unfortunatly the solution we found was really not satifying.
It relied on the cube being a bit tilted on certain surfices and the glitchy nature of the auto lock-on feature of laser-recievers in this game.
Also, you first screenshot shows how you use 2 cubes to get the laser in position, but that can't be a solution, right? you need 2 cubes at the end. Also, not sure if it's a bug, but we could walk through the cubes on this map. Standing on a cube was not a possibility.
However, this is how we solved the ending part:
http://images.akamai.steamusercontent.com/ugc/308863621377133140/B2ED06C043CF2A215373F589853342EC378B9C03/
(the laser is redirected only using 1 cube and the blue portals)
The puzzle took us 20-30min to complete for the first time.