After re-reading the original post, yes, Klaus is correct in that I was answering a different problem. My mistake.

However, concerning double-clutching, the act of transiting into the next gear (either lower, or higher) is the point at which the synchromesh operate. So, if you are already in the lower gear, and blip the throttle, you are matching the rpms at the clutch disk, but not at the synchromesh.

Occassionally (actally rarely), on this board, we've heard of someone wearing-out their second gear synchro, and that is the problem I was addressing(incorrectly addressing). But it is still a real issue, and if you have the ability to learn how to double-clutch, and you can benefit by saving your synchromesh at the same time, why not?