snoboy more to the point is whether you ever climb 11b well bolted slab than if you climb 10+ trad or not
by a 2 part system you mean like the Brits E1 5c or whatever one grade for the pro one grade for the moves?
i personally think a 3 part system would be best, one for technical difficulty, one for mental difficulty (exposure and runout) and 1 for objective hazard ie looseness, ankle breaking ledges and so on.
the reason for the 3rd part of the rating being I'd rather be 100 foot runout, or soloing, on bomber rock than 20 feet runout on loose choss.