I agree, and this goes with all blowers. Plenty of guys pulleying down and spinning Centri's faster than what is recommended. Doesn't mean you will make power there.
I would also take the CFM flow chart with a big grain of salt. The PD blowers are going to be more fun and will build boost faster. That doesn't mean they are faster, or slower. Take a ride in each. Personally, I don't like blower whine inside the car, since I owned a roots blower. It really comes down to what you like. Take your time and pick out what you like, and what you want to do with the car. Neither blower will dissapoint you if take the time to drive and experience both, not just through videos and dyno charts.