Winston
I've been able to get bevel-down planes working, with the soft drill-mounted buffing wheel and finer abrasive. I haven't used these blades enough to get a sense of far the blades would go before having clearance issues, though.

I have tried to do less buffing, and with a closer-to-tangent angle. Maybe that's part of it. With chisels, I just sort of stick them in the buffing wheel until they look done -- not much finesse needed. But BD plane blades probably need more care.

I'll try to get a profile shot of one of these blades later today. I'm not fully convinced that the differences in profile that we've seen between us are due entirely to the equipment; it may be possible to get similar profile with both types of equipment.

One more question to add to David's: for those that haven't had good success with bevel-down planes, what kind of problems have you encountered?