Guys, now I'll look really stupid, but I noticed that the pickups height in my SG were way lower than the regular factory settings. I didn't pay attention to that when the guitar came from the luthier. I adjusted it to the Gibson recommended settings of 1.6mm for treble side and 2.4mm bass side (it was over 5mm on the bridge and about 3mm on the neck), and all that horrible middiness GONE AWAY! Now my Black Dogs FINALLY sound just like that video of my previous post, even better! I can easily go from a low gain bluesly sound, to Jimmy Page like tone and to a very agressive early 90's AC/DC, Sabbath.
I will surely keep the Black Dogs on this guitar. Sorry for all the wrong information guys. An user from another forum said "something must be wrong. The guitar is great, the pickups are great, the amp is great, it's not supposed to sound like that", and he was right. The SG is sounding just like it should. It's ROCKING!
At least I learned a lot from most of BKP pickups! Thanks for the help!