I have been looking about to figure out our likes & dislikes in a potential liveaboard. I hadn't looked at the Catalina's until I came across this thread. I think I am going to take a look at a couple for sale over in Seattle. From the pictures I have seen online they look like a comfortable & efficient layout for a 36.
Steve - Be sure look at the MK I (pre 1992) as well as the newer MK IIs. In my opinion, the MK I is MUCH more functional as a liveaboard. You will find that you use the aft cabin for clothing and other storage. The aft cabin is far more accessible on the MK I and there is no waste of space with the bulkhead and door. In addition, the proper dedicated nav station on the MK I is probably the best I know of under 42 feet or so and it is a great computer desk for liveaboards. I can (and do) sit comfortably for hours typing reports for work. Just a few tips I thought I'd throw in.