Re: What do you wish you had known before buying your first boat?
I wish I had known how much I'd like sailing, so that I would have felt comfortable buying a larger/nicer/more expensive boat in the first place (the Pearson 28-2 is about twice the size of the Catalina 25). I learned tons by buying the Catalina and still sail on it often (the new owner is a good friend), but could have saved money by not buying and fixing up the Catalina first. However I learned so much from the Catalina that the shopping was a lot easier the second time around. The big things that drove the upgrade were the desire for standing room (nice if you cruise for more than a week) and more storage space.
On a 25' boat I'd prefer a real head to a porta-potty. It's not a big deal to maintain and it's nice being able use a pump-out instead of carrying the porta-potty off of the boat.
I agree that simplicity is nice, I just don't find a basic holding tank to be complex. The Catalina 25 was a lot easier to work on and far less complicated with an outboard engine, very simple electrical system (no shore power necessary), manual water pumps, and hank-on sails. The Pearson has more creature comforts (heat, pressure water, roller furling, inboard engine, dodger) but more to maintain.
boats that I sail on regularly: Pearson 28-2, Rondar 505, Yankee 30, Blanchard Junior