I just finished both routes and I really enjoyed this game.
I was expecting some kind of horror story with vamps as the anthagonist to eventually fall in love with, but it's much much better this way.
The game is a bit short. The endings are pretty good as well as artstyle (especially the sprites). well done voice acting.
I like the both girls but I think Carmilla's route is better. Not only because she's more my type but also it's a bit longer and more eventful than Elizabeth's.