I've been using the O3 White for several months and just got the Speedport Black yesterday. Last night I used the Black for several hours and thought I'd post my observations. My Speedport Black is strung with the open Speedport grommets, and my White is strung with the hard throat grommet. It's my observation that with these racquets configured this way, they are almost identical in the way they feel and play. I may have noticed a slight increase in swingweight on the Speedport Black over the O3 White, but it was barely perceptable. I may restring the Speedport Black with the string insert grommets and do another comparison later.