I've used both over the years and BT is what I stayed with. Recently, I've had issues with severe shedding due to meds, especially in the temple areas. I started taking EPO and garlic internally, which has siginificantly reduced the shedding. I started concentrating BT in the thinning areas and hair has already grown to where you can't see the spots that were there. Of course, the hair still has to grow to catch up with my other length, but BT filled in those spots in less than 2 weeks.
A couple years ago I ordered the sulfer powder with the intent of making my own sulfer oil, but it wasn't the same and I don't have time. I'll continue to order BT because for me, it has a proven track record. I've always noticed significant growth when I use it consistently (2-3 times per week). But this recent thing with my temples has me sold for life.