We just finished our first charter on a 444 cat after many years on a mono. Transition very easy and we opted not to take captain. Twin screws made maneuvering under power very easy.
I agree with all the benefits from above, room, stability, etc. our top end speed was just shy of ten knots.

Two downsides from mono that I experienced - minor items - just FYI - cats do not sail to windward as well as a mono (can't point as high); boat was harder to handle in the upper range of sail configurations (litterature said full main and jib to 20 knots, I found putting first reef in main at 15 knots improved handling and performNce). We had winter winds the whole week with speeds ranging 15-25 knots.

We will be on cats going forward creature comforts are top priority for my family.

Cheers,