Campy skeleton rim brakes on my roadie, bb7 road brakes on my cross thing, and avid ultimate levers / elixir calipers on my 29er. All three are great choices for the bike they are on and the style of riding I do. once set up properly, they are pretty much fuss free. I don't see any reason to upgrade any of them.
I don't race cross, so, that bike is just the missing link between the road and the 29er. It performs way better as an adventure bike than the other two. I'd put long reach calipers on it before I put canti's on it. I don't like Em. The bb7 is perfect.
Hydros definitely out perform mechanicals so I understand why racers will be going to them. It's definitely a step in a faster direction. I think it' a matter between what you need, and what you think you need. That being said, I don't need an ibis ripely with full xtr and enve hoops, but I sure do want one.