I just bought a new BMC TE-01 hardtail with full XO everything. Being mostly a road rider
needed a diversity in my riding. I hear alot of talk about XX being above XTR and XO being on par with XTR. Then some will say XO is only glorified XT...........BLAH Blah.
I rode xtr and it was flawless in all respects except I did find shifting to be more precise with XO. Braking was the same, awesome.