Sir John the Net Knight said:
How is that any different from Portal 1? It loaded after every chamber, if memory serves.
The original Portal was usually 3-4 chambers (depending on size/complexity) between load times, at least for the first 2/3 of the game.
Aside from the frequent load times, there was a clear lack of reaction/accuracy-centric puzzles as well. For example, in the original there were several puzzles that required you to drop a portal in a fairly small area while moving at very high speeds (typically it was along the vein of put a portal on a wall, jump into the ground and loop through a few times, then hit an angled platform or somesuch). These were conspicuously absent in Portal 2. I can only assume because the nature of controllers make such puzzles an order of magnitude harder to complete.
I'm by no means saying the game is in any way flawed, just that the design of the game was clearly skewed by the existence of a console version. There's a few other examples I had, but I can't remember them, probably due to lack of sleep. I'll probably contribute a few more if I remember them.