My first boat was a 1984 Oday 222 (22 footer). Great little boat, took good care of me and the wife while learning to sail. I had looked at an Oday 25 before purchasing the 22, and from what I remember, the main difference between the two were size, of course and price. I purchased the 22 footer for about half the cost of the 25 footer, both in similar condition. If I remember correctly the 25 had a head whereas the 22 doesn't.
Also the 22 has a retractable centerboard, great for anchoring out in small coves with skinny water. Like Pirate said, great little cabin for weekend trips. Be sure and rig you up a cockpit canopy to use while anchored. Being able to use the cockpit as extra living area makes the boat feel much bigger.
C&C 33 MKII