Regarding performance I'd have thought that once you get into the 40' range a comparable loa cat would outperform a mono in pretty much all conditions though e.g a Lagoon may not fall into that category. Certainly the cat we paced ourselves against last month was our equal hard on the wind and simply walked away when reaching.
I know it may as if I am trying to sell something but really for the first time I took a real interest in the cats around us this year and yes they did make a positive impression on me. Not they will are likely to change our ride. Looking at things like e.g Leopards indicates that such a move would easily double what we paid for the Malo. Bit rich for me I think.
Nonetheless the discussion interests me.
As I said, there are cats that are built for the space and cats that are build for performance and one of those built for space will have not a better performance than a performance mono-hull cruiser.
On the articles section of sailnet, that is unavailable (don't know why) there is a very interesting compassion between cats and monohulls made by a delivery skipper, one of the best I have read.
For what you describe to be your sailing season it seems to me that a cat makes a lot of sense and I am referring of those built for space and living aboard. Even those can sail pretty well, specially if compared with a mainstream cruiser. In Sardinia, some years back I meet an Italian that had sailed a 42ft Lagoon to Brazil, Caribbean and back and he was very satisfied with the boat.
My sailing season is a bit different. I like to have the boat sailing so In average I sail 6/8 hours a day, sometimes more and I like to push the boat (for pleasure) so a small cat (40ft) would be a bad idea for me, specially in the med where strong gusts from mountains are quite frequent not to mention that they provide indifferent sailing. A small cat requires a prudent sailor and one that sails always with a big safety margin.
These guys says about the same as I am saying regarding space and performance and they are heavy weights, I mean to Na Nigel Irens, top sailor Brian Thompson and top tester from YW sail magazine:
The fact they have not much thing to say about sailing is give you a hint that these boats are not designed to give pleasure as sailing boats. They work alright on autopilot and sail you to where you want to go but they are really about space and quality life at anchor. It seems they fit perfectly your bill
In fact what you do it is what most cruisers do and that's why they are so popular. It happens that most don't have the honesty to say that is that what they like most on a sailboat, it seems that you are one of the few that have no problem in saying that you stay 90% of time on anchor. I am quite sure you are not the only one, in fact I am pretty sure you are among the majority, unless we consider the ones that like most to be at marinas