I just demoed the OS today, and I was really impressed with how great the volleys and serve were (I normally use the Yonex RD Ti-80). I think I have to great a bit more used to the groundies with this racquet, but it sure worked out great for my doubles match today. So what's the difference between the OS and MP? The TW review says the OS is better for volleys, but it looks like the MP was overall a better racquet. Thanks in advance.