That's an interesting quandry that I face on my Westsail 39, which does have both. To this point I've not used the (Flemming) vane much, but doing so requires taking the (hard) dingy out of the davits and either towing it or bringing it onto the foredeck. Since I want to have it on the foredeck anyway when going offshore
and when use of the vane makes more sense than the autopilot
, this doesn't seem to present much of a problem. However, I'm not sure that on my boat
, given its greater beam, could even be hoisted in davits without fouling the vane.