Cnczone is pretty cool as a community, but I do think the reprap community is more helpful by an order of magnitude. Having met many members of both groups in real life, the reprappers are generally more approachable. I get the impression that every CNC build is a custom design "because I can" whereas most reprappers tend to stick to a few common designs and possibly modify them. Modifications that work generally spread back to the community really really fast and improve life for everyone. The #reprap IRC channel on freenode is an absolute goldmine of a resource, people with questions or problems generally get answers within seconds and it's active, fun discussion the rest of the time. Haven't seen anything equivalent in CNC (cnczone comes closest).