@damond: Do a google search about it... you'll find that they achieved it by eliminating the cups that are normally used to house BB92 bearings; instead the outer race of the bearing has the shape of the cup (with lip to control insertion depth). The claim is merely that the balls within the bearing are the same size as the balls within a standard BB bearing for 24mm spindle (but the increased ID from 24->30mm means there are more balls in the RF bb).
I knew that already about THM cups, didn't know RF made the same. Anyway, not an option to me because it means that for all the effects, the outer race of the bearing is also the BB cup which may be a bigger source of problems, specially if you ride much with mud condition it is not that strange that sometimes the bearings get stuck...now imagine this scenario with a bearing which's race is also the bb cup!
Seems the clavicula is staying hanging around and XX1 cranks are assembled for good!