That demo means nothing to me... I don't test my tractors driving up and down a road in high gear...
My tractors get pto work, the REAL test for hydro whine is, put something on the pto like a tiller, rev the engine up to pto speed and run the tractor at 1.5 mph, 2.0 mph and about 3.0 mph. Those are the most common speeds I do pto work, from rotavating, rotary cutting ect...
Every hydro I get in, that I simulate doing that, the hydro whine drives me nuts! I can't imagine putting up with that for hours on end!!
When I run my loader, I have the tractor at fast idle, and use a gear that moves me from the pile to the spreader fairly fast. Gear drive allows me to use fast idle and still have enough power to load the bucket at the pile.
NO hydro whine, NO loud roaring engine noise, and the diesel sips fuel all day long at the fast idle rpm...
I do like a hydro for mowing grass though... The blades make enough noise, it drowns out all other noises, so I wear ear plugs, with muffs over them.\
BTW, I don't and won't drive my tractors with the loader up in the air either!!
SR