[Big-Foot]

Drivers using Sequential gearboxes rarely use the clutch during up/downshifts - listen and watch carefully.

Feeling only marginally compelled to defend my position -
Having been a 5 time triple champion in SCCA competition, I've found styles that work for me and I teach those styles as well as continue to use them.
In the last 10 years I've had one single engine failure (Honda) which was of my own doing by having the short-track gear in the car running at Road America (on the track record BTW).
Leading the race 6 laps from the end, the she spun two rod bearings and a main. I could have clinched the Central Division Championship during that race but because of my finishing position being next to dead last, I had to work that much harder on the last race of the year - that was 2001. It was our 3rd Central Division Championship.

Sufficient to say - As a driver, I'll use every tool available to me to win. Unlike some, I don't see other racecars as "tools".
When the race is over and you've stood on the podium - it really doesn't matter what it cost to get there..
If you're not willing to push yourself and your equipment - you'll likely never taste victory.

-edit-
I should clarify that using your equipment to it's fullest does not necessarily imply that you are abusing the same..
I'm incredibly careful to not overrev the engine on a downshift - rather I am well below the redline when selecting a gear down..