I have a Black Dog in my SG's bridge and it works amazingly well.
I first had a 498T in there, then a Miracle Man and now the Black Dog and this is clearly my favorite. It doesn't have a lot of output but very complex mids and solid bass/treble. It doesn't scream, it growls very nicely. It often feels like it has enough power, but you do feel the PAF clarity typical of lower output humbuckers. I did replace the pots with new 500K ones to ensure it isn't too dark - the original pots were around 300 I think. This also brightened the neck humbucker up a lot btw.
So if you get one I would order some new pots as well at the same time.