My 9CAP has a standard, single band, module on 75MHz at the moment. I have been looking for either a 72MHz or 2.4GHz version, may have to send my radio and receiver in and get them retuned for a 72MHz channel. I don't know of anyone that has used the variable frequency module, so I haven't heard anything firsthand about them.
Speed, I only mentioned the S Bus servos because I see them on various vender websites and felt giving a bit of basic info on them would be prudent. I really appreciated you giving an example on their use in this case