I think MTrn is probably the type of thing your looking for, not so much size gains but good strength gains. Superdrol kicked my arse with back pumps, couldn't dl and could barely squat, but Mtrn with taurine, no problems. I haven't seen anyone else get back pumps either, Ryansm has one of the early logs on Mtrn solo, it's a good read if your thinking about it.
Very little shut down, easy on the liver, no BP issues and good strength gains, it's good stuff!