I would assume everyone has his own oinion of what BBS actually feels like, but I think it really refers to what a baby's butt actually feels like -- smooth as silk. That's what is probably meant by achieving a BBS shave. When your fact is THAT smooth, you've achieved BBS status. Personally, I seem to get an extremely good shave every day. Is it BBS? Well, as far as I'm concerned it is. Even going against the grain there's either no or very little resistance.
I'm sure that's not as definitive as you'd like, but I'll bet you'd get ten opinions from 9 responses!
"We are not in danger of dying at the hands of toiletries!" -- A British airline pilot