Blood hunter opinion

Hello, I am going to be playing a blood hunter in my groups up coming campaign and was wondering what everyone's opinion is on the class/ subclasses.

What do you think of the base class and what do you think the best subclass is? Are they all usable or are there some that should be avoided? Would I need to multiclass to make it work or can I go pure blood hunter?

Im currently thinking of going ghostslayer or profane soul. But im not too sure about the fact that there's only 2 pact slots even at level 20.

Any advice would be appreciated.