a) where do you ride?
b) how much do you weigh?

I wouldn't describe the technology as immature, but certainly on a different part of the maturation curve than rim brakes. Rotor technology is advancing to better control heat build-up (Avid HSX, Shimano ICE XT). While fork designs may not yet have been optimized, reputable manufacturers will add extra margin to safety critical components unless they are specifically design for high-end race applications.

I've found discs to be very easy to keep in adjustment and the difference in control and security on long descents is significant, but I weigh 200 lbs. The less the combined weight of rider and bike, the more braking will be limited by the tires. Many riders at my weight are comfortable with calipers on big descents (we're talking switchbacks of course) so YMMV.

I bought a first year Volagi with the 130mm rear hub spacing. In my mind this was the only quirk, similar to Santana's 160mm rear hub spacing. This isn't an issue other than smaller selection of hubs for a second wheelset. Current Volagi's have the more standard 135mm spacing.

Most of these threads have anecdotal and otherwise stories of difficulty adjusting disc brakes or even just getting the wheels back on, but I haven't found this to be the case at all. Why just the other day my son (37 y/o of above average intelligence I think) managed to put the front wheel of the Volagi on while I was changing into my cycling clothes. By way of comparison, I'd say there is more "art" to setting up FD and RD, maybe verging on black magic judging from posts on the subject.