Never ridden a disc brake CX and I've just upgraded my own CX to Avid Shorty Ultimates which are more than good enough, but I'd like to do a test sometime to see the difference. When my current CX bike gets wrecked I 'may' go disc....
Hearing the commentary during pro-races and reactions of the pro-riders (and results of the choices made). It seems that the best choice is really depending on the circumstances.
Disc brakes seem to be worth considering when riding:
- Fast dry tracks with lots of corners and/or hills with down-sections (better, later breaking)
- Muddy tracks that are flat and without long running sections (less interferences of mud in the brakes)
But muddy-as-hell tracks with long running sections and/or with "cycleable" climbs are -so far - better with the lighter bikes.
(All energy savings matter at the end of the race)
We haven't had snowy or frozen tracks yet this season, so I can't really comment on those yet.
(Although frozen tracks are probably similar to fast tracks)