I don't own a Flyer rib, but I have owned one of the 440's for a few years.
It generally does okay, it's perfectly dry even on rough water, but wind does tend to blow spray over the person at the wheel, and anyone else on the back bench. The driving position is also very low, making it difficult to see at times, and also more uncomfortouble if you slam!
It also does okay in rough water, but it does tend to slam a bit now and then. If it's flat enough, then 40 knots is esily achiveable with a 60hp engine - So it's generally a nice boat, but we are thinking of selling it for a bigger RIB - For dryness, and a better driving position.