You might want to be more specific as to which Cary amps you are considering mating to either speaker. (Cary amps range from 3-watt 3A3-based SETs to 250-watt Push/Pull designs.) My guess is that the ProAc's would be easier to drive with tubes--and only try it with at least 80 P/P watts.
I am wondering, myself, about powering F30's with Cary's switchable 95-watt (triode) or 165-watt (tetrode) SLAM-100's. If I do try that combo out, I'll let you know.