RE: to loop or not to loop?
While some may find downward pressure to be somewhat of an advantage, it canbe VERY detrimental to those who have the tolerances 'stacked' against them. It could make an otherwise correctly spined arrow and turn it into something that wouldn't begin to work correctly/effectively.
Shorter ATA bows combined with longer draw lengths and marginally correct spin is a recipe for disaster. The addition of something so small as a loop could be the formula for success.
Couple this with all the other benefits and it's hard not to utilize one. The sad part is that someone who has been set up with too long a draw length, which is more common than many could imagine, can be hurt moreso by the advanced/lost anchor.