It's good, but I'm not sure it's as good as it's being made out to be.
It's challenging, and for that reason it'll be good for many hours of gameplay.
However, you spend a lot of time traversing the same areas over and over, and there's a lot of stuff hidden out of the way that it's very easy to miss during your travels. Getting killed is frustrating as hell, because you go back to the Hunter's Dream and have to travel to where you were all over again, which starts to get really tedious. You will get killed a lot.
Also, if you don't have a Souls background as previous, there's a lack of bedding in, there's very little tuition or practice, you're thrown straight in.
I've had to learn a new style of gameplay too, as my approach in combat games is normally to be cautious and pick off the edges first, but you can't do that in this game, it's geared towards making you assertive and being on the front foot, the guns are crap, it's all about melee, the guns are only really used to stun your opponent so you can melee them.
I don't think it's the sort of game you can play hour after hour, because once you lose to a boss a couple of times, you get sick of the repetition and have to put it down and come back later, which might be a good thing in the eyes of some.