I'm a Bio 300 user now and I actually have kept mine 100% in stock form. No dampener needed with this one and even the stock grip is fine without an overgrip. Although it is a touch tacky right now, but that will ease off I'm sure in time.
And for those who'd want to customize, all flat edges for lead tape.
"Tennis is just chess with balls."
Using: Dunlop Biomimetic 300