I sailed a number in this range and INHM... go for the Catalina 25.
Don't go bigger if you're hesitate.. we've sailed happily with 4 and had 5 on the Catalina 25. It outsails the others at the price point.
You'll be spending lots and lots of money after the initial purchase. LOTS.
A few things about my family: My kids are 23, 20, and 13. Although they like tubing and waterskiing from our little power boat (1991 15' Trophy w/ 50 hp outboatd), none have ever been interested in sailing. When on vacation at Lake Wallenpaupack, the highlight of the whole week is the 2-4 hours/day my wife and I spend sailing the Phantom while the kids occupy themselves doing other things. I would like to duplicate that experience closer to home with a boat suited to the local inland waters.
I've seen a lot of advice to go larger than 25', and I am not sure what to do at this point. I am budget conscious, and the jump from 25' to 27' seems to entail 2x higher displacement and 2x higher price. (I guess they sell boats by the pound.
) With the 13-year-old staying home, I expect to do day sailing the vast majority of the time. Although when he goes to Boy Scout camp or on a church trip, we might venture out for a couple of overnights. As Jim pointed out, the importance of live-aboard accommodations goes up the further away the boat is moored. So if we keep it in Essington, very little need for large cabin. If we are further, then larger might be important.
I've been really impressed with the "little" Catalina 250. The open-cabin concept with no partitions for the v-berth or aft cabin gives it a very roomy feel, and without the kids staying overnight we don't need to privacy of those partitions. The pop-top seems to help head room in the galley. I'm not bothered by the Porta-Potty - we have an almost identical one for our power boat. I actually like the removable ice chest better than a built-in one. I love the cutaway transom with swim ladder (nice if we could find some swimmable water somewhere), and one of the boats we are looking at has a steering wheel helm which seems to open up the cockpit quite a bit. There is very little teak on the interior or exterior of the Cat 250, but the sterile look did not bother me.
I have not gotten to see a Cat 27 or 28 yet, but did get to see an O'Day 302 and another boat by Hunter. And the 250 just seemed to have a lot of the "big boat" features in a smaller, less expensive package.
One thing that I admit I am not sure of is the headroom issue. It did not bother me having to duck a few inches in the cabin - I would expect to be sitting down in the cabin if I am there anyway. But I need to spend some more time and see how it would affect me.
I am open to any suggestions from you around why I should go bigger. I do not want to end up trading up every year, but my history with the Phantom and my little power boat suggest that I'll stick with what I get for a long time. So I might as well get something I will stick with.