I only really liked maybe 2 arcs of the VN. I also didn't like the final arc at all, so I have low expectations for what they're trying to accomplish here.
Chiwa Saito is great in this role (VA for Kotori). Best girl?
Chihaya is pretty funny too.

Having played the game, I'm sure I'll enjoy the anime well enough. Not sure if I'd recommend it yet though.