i've only just noticed this thread...tried to skim all 11 pages but might have missed something so, my 2 bobs worth :
done more than a few off-shore miles on monos (albeit mainly light weight
race boats) and recently converted to cats, so i've got some ideas. the motion on cats is much shorter and quicker, and in the wrong sea can be quite taxing...but is still much easier on the crew and safer than the movement on a mono
moving around on
deck on a cat is safer by at least 10x.
ease of sail handling the same
benefits of staying flat cannot be overstated
overall if you want space, comfort and
safety in most situations (the others are dealt with elsewhere), then cats have it hands down.
cheers,