I guess "uberfast" shifting is up for discussion. When I drove American muscle (in my day), speed shifting on the strip probably was done in a split second, like, maybe quarter of a second. You poised your foot above the clutch and when it was time to shift, you stomped the clutch hard as you shifted to the next gear and took your foot back off as fast as you could. You NEVER lifted your foot off the gas. Like I said, about a quarter of a second. During this time, you moved to the next gear. And, it was always slammed into the gear. Syncros in those days didn't seem to mind.
These days, nothing seems to be made that can shift like that.