My playthrough was almost the same as andyb's.
There were some areas that I didn't have to go to solve the puzzle: the angled panels on the walls and the white room on the right from where the player starts.
The pedestal button's timer was really tight (I like that way). I had to try a few times before being able to perform all actions in time.

Vfig: or just be verry quick on your way round the column to that Cubespawner-button, then you need no Portal on the first Half of the Map.

My playthrough
http://www.youtube.com/watch?v=zGYl6vIaopk&feature=youtu.be

Turn off bridge, use faith plate. Place portal on wall near bridge switch, and on wall beside the ramp leading to the cube switch. Walk through portals, turn off bridge again, walk back through and press cube switch. I thought that was the intended way to solve it...!

The pit is purposeless? People are still finding ways to solve these I'm not expecting. How did you get the cube?

The opening room felt quite confusing. A lot of elements, and some of them--like the pit in the room to the right--seem purposeless. The second half of the puzzle--once you had the cube--was better.