We were long time mono sailors and tried a cat a couple of charters ago. Will probably never charter a mono again and if and when we buy our own boat for cruising it will be a cat. They are easy to live on and with twin screws are very maneuverable. Some cats perform better than others so if you are concerned with that do your homework. If I wanted performance I would look at the Catanas from Dream Yacht Charter or the Voyage boats.

Also, I feel that cats are safer than monos. Aside from the very light, high performance cats, they just won't capsize. Even if you did manage to somehow get one upside down it will continue to float. They are stable and comfortable under sail and much easier to handle under power IMO.

As far as the captain, you probably won't need one for more than the first day. Most mono skills will cross over and the new skills are quickly learned. I took a weekend mulithull course before our first cat charter and even with several other students in the class we were able to cover the new information very quickly. With a teaching captain focused solely on you I would imagine you will be able to cover everything within a few hours.

Whether cat or mono - have fun!