I usually use base same as you, had black tar once as it's not very comman in the UK. It tastes fucking awful compared to usual base heroin, and I mean has you gagging bad. But other than that it's much the same, the stuff i had wasn't as strong as what I'm used to but i guess that's just a batch thing, but it vapes off foil much the same so no problems there. Enjoy hope your experience is better than mine was.