I currently have Bloodborne ahead of Dark Souls 3. It's a bit premature to judge, given that there will be balance tweaks and DLC coming, and I haven't even completed a second playthrough. But as of right now, I do prefer the combat, setting, and backstory of Bloodborne.
You can employ a dodge-or-parry style in DS3, but everything in Bloodborne was designed around that style. In DS3 sword-and-board is still the norm, I'm pretty sure.
On occasion DS3 really feels the weight of all the DS1 references it's forced to carry. For example,
NB: I'm not saying DS3 is a bad game. The level design and art design are outstanding. There were some really rather neat encounters and boss fights in there. I'm glad I bought it and will almost certainly buy the DLC when it comes out.