We have lived in Jacksonville for 6 months and have been really disappointed with the lack of fun, meaningful things to do in this city. Needless to say, we found out about Catty Shack and jumped on the occasion to check it out. We absolutely loved it and would definitely go again. I think the fall and spring are the best times to visit only because I would imagine that the cats are tired and sleeping in the hot humid summer. Wear comfortable walking shoes and a light jacket if you go in Dec/Feb. The only bathroom facilities that I noticed are the porta-potties so don't drink a lot prior to going.
The money you spend to get in goes towards protecting the animals (it is entirely volunteer based) so you feel like you are doing your part in helping. Highly recommend this place for people of all ages, totally worth the drive! Oh and if you bring your kids, don't let them scream and run around, it's rude and distracting to others, plus it irritates the cats.