I'm only a 3.0 bordering on 3.5 and have played with racquets from 90 sq in to 107 sq in. I predominantly play doubles and have come to find that I like using the PSBLX90. I enjoy the stability and maneuverability that the racquet has. I play a 1HBH and it just feels better with a smaller head racquet. I have long loppy swings so a heavier racquet feels better. When I play with 100 sq in racquets, I feel like I have to play with much more topspin which causes me to mis-hit my shots more because of the extreme brushing up on the ball. Also, as someone said above, at my level I've come to realize that control is much more important than power, but the heavy smaller head racquet still gives plenty of power on regular rallying due to it's weight.
Pure Drive 2012, Yonex VCore 100S, Pro Staff 95S. Pro's Pro Strings. Klippermate stringer.