I respect your experience, but am not worried in the least. The motor series I have is the same one used in so many commercial and offshore boats, and those guys punish those motors day in and day out, yet seem to have little to no problems with them. I very rarely go wide open, or anything close to it, keep up on all my maint and believe this motor will last at least as long as any 2 stroke I've owned. I've never met anyone with a Yamaha 4 stroke in this series of motors that has a bad thing to say about them. The SHO has had some teething issues, though.
Fuel mileage is worth talking about, IMO, and it was a big part of my decision. In the performance bulletins the manufacturers put out, this series of 4 strokes is much more fuel efficient than the Vmax. According to the bulletins for my boat/motor, at 3000rpm, which I cruise at quite a bit, my motor is 20% more fuel efficient than the 200 VMax that I had them pull off to put my 225F on. When you add that to the no buying 2 stroke deal, the running costs will be cosiderably decreased over the life of the motor. I have to change the oil every 100 hours, but the total cost of that is easily less than 2 gallons of 2 stroke oil.
Not putting down the 2 strokes at all. They are great options, too. I just don't think anyone should be scared of buying a Yamaha 4 stroke.