Both bikes are excellent, for what they are, which are small slow moped class scooters. The Honda has a 4 stroke engine, and I may be wrong, but, the Yamaha Vino originally had a 2 stroke engine (that may have changed for 2007??). I personally would prefer the 4stroke, however, Yamaha most certainly knows how to build excellent 2 stroke motors. Correct me if I am wrong, but, isn't the metrpolitan II the faster non-moped class scooter that will need to be registered as a motorcycle? If thats the case you might just as well spend a few more bucks and get the larger Vino 125. Of course, dealer location, reputation, and what you can talk the dealer into throwing in may figuere in also.

Unless you alter the Honda, the Yamaha is the superior of the two. The Metropolitan II is heavily restricted to comply with moped laws in some markets. That means a top speed of about 25 mph. If you are handy, you can derestrict it to make it comparable to the Metropolitan I. First and foremost, remove the restrictive gasket on the intake-that will help you the most and it's a pretty easy alteration to do. Second, replace or alter the variator so it is like the Met I. You may also need to change out a few other items to get the most out of it, i.e. engine control module and wiring harness(or you can rewire and reprogram if you're good at that sort of thing), final drive gear(the Met II has 47 teeth to the 45 teeth of the Met I), the carburators are different but just replacing the diaphragm spring instead of the whole carb will do the trick, and finally, the lobe heights on the cam shaft are different between the I and II. Honda went to a lot of trouble to build the Met II for its particular markets and derestricting it isn't a weekend project for most people.

With that being said, the Vino has slightly better low-end torque than the Met I, but the Met I has a slightly higher top speed. When I'm riding my Vino with my friend(who has a Met I), I leave her in the dust at every stoplight but she eventually catches up and passes me after a couple of miles. Other than that they are too similar to say one is better than the other. I brake better than she does but she gets a smoother ride. That could be differences in the particular bikes rather than differences in model design. Both are very easy to work on, very reliable, and inexpensive to operate. My 6,000 mile tune-up cost me less than $20.00 in parts and supplies.
Feel free to e-mail with any further questions. Happy scootering!