My opinion after having used both?
wush.net by a mile, wush.net’s customer service responds in minutes, and the big difference is that wush.net isn’t going to try to gouge you with extra fees. I signed up with CVSDude because I wanted to get out of the business of hosting SVN, but after all the various fees, I ended up paying something like $47/mo. just to host a few small repositories. CVSDude wanted to charge me an extra $10/mo. for the privileges of having access to backup files. Also, CVSDude has a difficult to use administration system.
Anyway, if anyone is considering the two – go with wush.net.