Ran it once, plan to run it again. It's genuinely wonderful.
It takes the basic Black hack system and adds lots of excellent weird fantasy flavor - demon pacts, weird technology, intelligent cursed weapons. Perfectly captures the whole Elric-style fantasy genre.
It's also got tables for creating a fantasy world and a fantasy city.
Black Sword Hack is a pretty narrative rules-light system, and while those are great to bring to the table when I'm just running a game at my FLGS or RPG Club, for a long term campaign I'd rather have a few more campaign tools and deeper systems. So for my long campaigns I use systems like Forbidden Lands, ACKS, WWN, or at minimum OSE with something like Into the Wild bolted on.
Ran a public game, group had a blast. It's very easy to run, but the spells/powers look Like they might be easily be exploitable given a more powergamy group.