I enjoyed Black Mass.
It’s really well done.
It has about 237 f-bombs, some violence (but to my way of thinking, not tons or too much), and communicates the life and times of James “Whitey” Bulger very convincingly.
I’d give it about a “7,” not a “10,” primarily because although it is enjoyable, and serviceable, it doesn’t quite achieve “the x-factor” on any grand scale.
Depp, of course, and the entire cast, is on point and wonderful.
Depp loses himself in the portrayal. His hair, eyes, prosthetic nose tip, make-up…nothing about his physical transformation is distracting (which is, in and of itself, amazing and Oscar worthy).
If you like mob movies, the sort in which people get banged around and includes smoky bar room shenanigans and back office deals, well then, this is your show.
p.s. For the record, Black Mass is way better than Mortdecai.... :-)