Yetiman: I used to speed shift regularly back in the day, but the first time I did that autocrossing in my 365 HP Stingray with some brand new 11" slicks, I stripped my spider gears and had to limp home, clunkedy, clunkedy, clunk.
I may shift my Cobra quickly when necessary, but now the right foot comes off the gas, ever so briefly. I have beefed up my Jag rear end considerably and so far it hasn't given me any grief. Rich