I can understand the modulation aspect, I havent ridden a bike with disk brakes, but have lots of experience with cantis and v's.
When I bought my last MTB, it came with disc brakes. It was my first disc braked bike. I was really wanting to get the bike out because it was light, had a cool frame and new suspension. The brakes were a complete 'meh'. I didn't care. With V brakes the limiting factor was almost always traction on a loose surface anyhow.
I came away from that first ride I was completely blown away with how nice the discs were and how much I had underrated there ability to improve the entire package. I guess that's why I'd really like to see them on a CX bike now.