I'm interested in a 2007 Castro Valley which comes with a Shimano Dynohub for the light. I will most likely not be using the light at all, as this will become my all-rounder rather than a purpose-built commuter. It will be used on and off-road, and possibly for some CX (I have drops, road levers, secondary levers, Shimano 9sp bar-cons and Paul Thumbies ready if I pull the trigger), which is where this question begins.
How much speed do these hubs scrub off as a rule? How heavy are they compared to conventional hubs of roughly the same quality? I'd likely be using almost everything currently on the bike except the cockpit stuff, and don't really want to invest in a second front wheel. Can this wheel be used at all for CX/offroad, or is it too heavy (or too friction-y) for anything but touring/commuting, where the necessity of a light would take priority over speed? Posting here instead of the CX forum because I figure you guys know more about dynohubs than the CX guys do, and here instead of the Touring forum because this bike really isn't a touring bike, what with the flat bar and all.