I've just given up on a Volkl Organix 10 after a year of good service. I picked up a Wilson BLX Six One and instantly felt like it was moulded to my hand. I enjoyed the X10 and played quite well with it but the grip shape, as well as the sponginess of the handle system makes the bevels feel indistinct and it was endlessly annoying on serve and overheads. The Wilson feels great in those departments. The serve just seems to sing. I know it's probably more to do with balance than with grip shape but it is certainly a factor.
“There is no best. There is just the discussion of who is best. Federer, he will always be in the first part of such a discussion.” Rino Tommasi