Never played a Souls game, but I bought it and have been playing every night. It's difficult, but definitely rewarding (I was just about ready to uninstall the game on the first night, but I persisted and I'm glad that I did). It also has a very awesome atmosphere, don't want to spoil anything.
It's quite refreshing to play a game that doesn't hold your hand at all in terms of what to do and where to go.
Edit: The multiplayer aspect of it is interesting, with all the notes scattered around you don't quite feel alone in the world. Haven't tried pvp yet though.