Later is better
Roger Macgregor doesn't change his designs unless there is a good reason. Because of that, generally the later the year the better the design. If you're looking for a relatively new 26X, I'd recommend 1999 or later just because some of the 'bugs' had been worked out in 1996, 1997 and 1998. The earlier Macs (26 on down) generally follow the same rule. If you're looking at a 26 and want superior sailing capabilities, I'd recommend the 26D (dagger board). It's not as pretty as the 26C (retractable centerboard) inside the cabin, but it is a better sailer and doesn't have a centerboard winch which tends to need replacement after about 10 years.