If I could answer in addition to Mike...NetDoc:So Mike,
do you think the guy was writing a critique for cave/wreck/dir divers, or the average Joe?
The author was obviously writing for the average Joe, who's vertically trimmed in the water, because, speaking from experience, if you're in correct horizontal trim, you don't even THINK about using the shoulder dump.
Which brings us full circle back to the horrible teaching that passes as "lessons" that's rampant in the recreational scuba industry. But that deceased equine has been flogged oh so many times before.
Personally, I feel that every time an instructor uses the shoulder dump (except when leaving he surface, perhaps) in front of a class he's doing his students a disservice. Students emulate their instructor. If the instructor almost exclusively uses the rear dump, the students will. And in the process of using he rear dump, the students will figure out if they're trimmed wrong -- collateral education.
So, again, yes, it's written for the "average Joe" because if you "average" ALL scuba divers, average is in pretty darn bad (and, among other things, vertical).
Roak
Ps. Pete, I'm being serious, I'm not taking a poke at the Buddha hang stuff.