Interesting points on the barends, I'll look more into that option.
I was in another LBS asking about SRAM Rival, I'll see what the guy can dig up for me on that front. He reckoned Ultegra dual-pivot brakes should have plenty enough stopping power, the only question would be clearance issues, which looked tight given that I looked at it with roadie tires there. Fenders and fatties, no chance.
A really good point he made was that the new Trek Portland is Ultegra equipped with disc brakes, can anyone tell me more about how this bike is set up? Anyone have pictures? I'll have a look and see how Trek have done it.