6-8th is the best. It's the closest you can really get nowadays within rooms in most sites without being labeled a godmoder. As long as you build the character sheet correctly and don't go overboard with blah blah blah I learned this power from a Salubri, and I'm a Tremere who has never diablerized in my entire undeath, it's fun to play an elder vampire who knows stuff, and can handle their own in nightly situations.