Hi,
I think it would be worth it to at least try the stock shaft - Over the first 7 rounds of the year for me, I've used my new G-10, and have just fallen in love with this driver.
My swing speed was between 95 and 98, and I don't really 'go after it'. More of a smooth swing. I ended up with the stock TFC stiff, and 10.5* loft. Absolutely perfect for me - flight, control, the whole 9 yards.. Kind of unusual for me, since I've typically been fitted with regular shafts - But in this case, everything measured said the stock TFC stiff.. Maybe because of their slightly longer shaft length(?).
Regards,
Scope