I just finished Bloodborne and have started DS2:SotFS, about 30 hours in. Here are my impressions:
-I would say it is worth getting if you're a fan of the genre in general.
-If you've never played a 'Souls' game before, you might want to look into understanding the whole "hollow" effect as coming from Bloodborne, you might suddenly be wondering why you have only half your health bar.
-For the most part, you need to take any fight slower than you would in Bloodborne. Mistakes are painful, and there's no "quickly attack your enemy to get your health back" mechanic. Even going back into a previous area, if you're trying to rush through and make a mistake in a pack of enemies, you're more than likely dead.
-I played a dual wielding build for Bloodborne, and am going tanky for DS2. It just feels right with the need for stamina management and shields play a huge role in survivability.
-Your character is slow. S.L.O.W. Which goes along with the tanky feel.
-I am playing the PS4 version - it does not look as nice as Bloodborne overall, as it was developed for the previous generation initially, but it plays at a SOLID 60FPS the whole time so far an doesn't really look bad; I think it's mostly a change in the art style. You can tell it's playing better than on the PS3 and better than Bloodborne. With that said, I find the controls are responsive in the PS4 version.
-A lot of weapons and armor to choose from, which might make it seem overwhelming coming from Bloodborne. Rest assured you can complete the game with any single one really, so just focus on which one has a move set you like.
If you like to PVP, it's still pretty active.
tl,dr - get it. It's fun.