I'm not sure whether dropping a bit of string tension might make the sweet spot feel bigger. I must admit I don't find it too small on mine.
I also added a leather grip to mine to give it more static weight and make it a touch more headlight. I guess it effectively turns it into the Tour version but with a 16x19 pattern and 1 extra square inch.
Ive tried a few rackets and settled on the Bio 300. Its a really nice racket to play with. Plenty of control with more than adequate power once the leather grip is on.
Lee, how are you finding your Bio300 Tour?
"The older I get....the better I was"