You mean rev match it? Yeah its fun but a little too much all the time when you have to slow down quickly with a trailer (I know tractor trailer drivers do it though). Ive actually found shifting without the clutch in a diesel is easier just because of less rpms. Wouldn't not shifting down at all wear out your brakes even quicker than an auto? I always downshift and my clutches last a long time,my 6.4's stocker looked brand new with 80k on it, at least 40k towing. I'm not arguing that it doesn't speed up the wear by any means, that makes sense, but I think if you're sensible it shouldn't be much of an issue.
