Just finished it. Sorta lengthy write up below.
Really good, though I'm not sure how it stacks along with the other Souls games yet. Starting up a NG+ game.
I think the biggest strength of the game is the setting and tone. I LOVE the Lovecraftian elder god kind of mythos and while we've gotten some of the in the other Souls games, this one takes that and turns it up to 11. In fact I might say that aesthetically this nails that kind of tone better than any piece of media I've encountered yet. Especially toward the end when every monster just looks completely jacked.
My biggest problem with the game (besides load times... yeesh those are awful) so far is that it didn't feel like you were rewarded for exploration like you were in other Souls games. In those games exploration might unearth a cool new item or armor however this game's very restrictive weapon-set and interchangeable armors made that not really an incentive. While the weapons are indeed amazing (I used the cane-whip and mercy blades in my run), the very limited selection meant that you weren't finding items very often. And the armor didn't vary a whole lot statistically which meant it felt like every piece of armor I found was mostly just for aesthetic differences.
As a side note, I felt the game may have been a bit short (my finish time was somewhere between 30-35 hours) and I had a MUCH easier time of the bosses than I usually do in a Souls game. Now I definitely didn't uncover everything and I didn't spend much time doing Chalice dungeons, but I felt like Dark Souls 1 and 2 were more in the 50 hour range.
As for bosses, I only died on 4 of them, and 2 of those I beat on my second try. The other two were a half dozen tries each, but one of those was the first boss where I will still sorta coming to terms with the mechanics. One thing I noticed early on is that while the general strategy in bosses in Dark Souls 1 and 2 was to circle strafe and wait for an opening, the strategy for most bosses in Bloodborne was to wait for the boss to start their attack animation, dash or back out, and then once it's finished close in for a hit or two. If you're having trouble on a boss, try to stay in front of the boss, relatively closely, and wait for them to go through their attack animation, then dash in. Works on most of them, especially the "Beast" ones.
I do like this game, but I do think that without the kind of build variety and the sense of exploration you get in a Souls game, this one might have less staying power. I felt like maybe I enjoyed this one while I was playing it more, but that I'll probably not play it as much.