I've sailed a little on the F34 and they really sail great but I can't comment on cruising one.
I did cruise
for a week or so on a borrowed F28R though. My wife and I sailed from Clearwater to Boca Grande and back, living aboard
. Fun, fun, fun but it was truly camping. We left Long Boat Pass in the early am with a 25k easterly breeze and we anchored up off Useppa at 1pm. We hit 18.5 knots with the auto pilot steering
and me playing the mainsheet, straddling the aft beam, getting soaked everytime the aka hit a wave and grinning like the Joker.
Raced the same boat many times, great fun especially when you could get the main hull
flying. There's nothing like sitting on the windward ama, making 18+ and steering
with 2 fingers on the hiking stick.
Wonderful, fast machines.
My Stilleto 27 also made it past 18k a few times but man it was a serious handful to steer. You had to concentrate 100% or you were going over. It could switch from weather helm
to lee helm
in a flash.
The F28R on the other hand was way more stable and not squirrely at all. I always felt in control with the f boat, not so on the S27.