For 1 hour match, I do not use it. But when a match starts going over 2 hours, I have to switch to a lighter racquet, or I'll start losing badly.
Interestingly, none of my opponents do this, and I can see them visibly struggling, getting slower and slower, and not being able to swing in a timely manner. They just punt the ball back to me, with no force or direction.
The only people I have trouble with, are the ones that start out with Head Exteme... Those are hard to crack, as they do not yield as the time goes on.