I played through twice. Once completely good and once completely bad...depending on how you see it and how you feel about the girls...
It's a weekend rent for me. Fantastic game, but nothing really to go back for...even the double endings weren't that great. It's not like gameplay changes to get you there, just what you do in one particular moment...so wouldn't have felt guilty checking youtube for the other ending now that I've done it.
I do think everyone should play it through once though...but maybe owning it is a bit much.
Paul