The difference is Bloodborne framerate stays at 30 almost all the time and there were only ever frame pacing issues in co op with multiple players with different connections. The framerate drops on occasion in single player, but nothing that really detracts from playing.
Watch these two videos Bloodborne barely goes below 30 meanwhile Unity struggles to struggles to hit 30 almost the entire time. These frame rate issues are clearly worse in Unity. IN fact it seems to AVERAGE in the low 20's. (to mid 20's)
Even after the patch Unity still has a consistently terrible framerate, especially in crowds.
Granted it appears Unitys engine is doing more it is clear the frame rate was a much bigger problem in Unity than Bloodborne.
Bloodborne like Dark Souls has frame rate issues in very specific instances and they are generally VERY spread out.
There is nothing like Blightown in this game.
Meanwhile it appears that unless there are no NPCs on screen Unity pretty much never hits 30 FPS.
Now this is just the opening level of each game, and I haven't played Unity myself. But it seems clear that it's choppiness was much more prevalent and happened on a more consistent basis.