So have I. Unfortunately my internet is really slow.

I never tried portal 2 coop

portal 2 coop is awesome, plus then there are workshop levels for coop so you can keep on going

If you will have a chance, it's really worth to play it. If not for game alone, then to see the ending.

Just recently played through it with boyfriend. It was quite fun. I don't know if it counts as a plus or minus for you, but it's not as challenging timing/precision wise as the solo.