I've raced both and like 'em both. The Yamaha definitely faster but the Maicos handling and tractability are so much better than that of the Yamaha your lap times would be much quicker. The Maico isn't unreliable either. Those old 250s are so understressed they go on forever if they're set up properly and treated nicely. I've got no hesitation in picking the Maico (with the Yamaha front brake).