In terms of what is the better chip, there is still no evidence that fc-pga is better then slot design. Both have it´s pros and cons.
I have and Bx6 rev 2 myself and upgraded from a celery 366 to a P3 700E Slot 1. Since I knew that it will be the last chip in the board
and i intend to keep the system that way rather than strip it for parts, it seemed unlogical to choose fc-pga. Also, take into account that fc-pga are more senstive when installing them. Since it is quite hard to find a slot 1 these days, it sadly leaves u little alternatives.
My cbo p3 can do 1ghz at core voltage with cas 2-2-2 ram btw..
Im not the overclocking freak, but these 700e really overclock well.
The 933 setting is VERY achievable at core voltage on the bx6rev2...