Well I beat it a couple days after launch, still waiting on my coworkers to beat it so I can play some co-op. Still not sure how I feel about the overall game. It was fun, but the puzzles felt more chaotic and forgiving. What I mean is, I didn't feel quite as proud solving the puzzles, because it seemed like some of them were just by chance. For example, I'd walk into a room in Portal 2, and it would just seem daunting, and I would have to study it for awhile until I discovered the solution. In Portal 1, I would start to solve it only to run into a brick wall and realize my approach was all wrong.
I do have to say I'm enjoying the ending song after a couple listens, it didn't seem as catchy at first but now I love it.