About the agitate stroke on Whirlpool DDs...
I am right there with everyone else in that I dislike the short, fast agitation stroke. I am quite sure though that this was designed on purpose as a solution to creating enough water current in a tall slender basket to allow for good roll-over. I'm not saying it was the right decision, but I think that's why it was done.
If you look at the history of Whirlpool's belt-drive machines, little to no real development was ever done on the standard capacity machines in regard to functional design alterations that would affect wash performance. From the beginning, there were Roto-swirl, straight-vane, and Surgilator agitators, and they lasted the entire near 40-year production span. The basket size didn't change much, and I don't think anyone ever complained about them other than for lack of overall capacity.
The large capacity machines though had initial problems moving clothes. The first agitators were enlarged versions of the originals, but they tore up transmissions. The next batch (the penta agitators) didn't wear the transmissions, but people complained of lack of rollover (when over-stuffed). The Dual-Action was the result, which is better, but a highly stuffed machine can still clog-up.
The problem was attributed to the height of large capacity baskets, since they were taller than standard, but not much wider. Seems that clothes could only 'climb' and roll-over a certain height in a basket with the long stroke. Since the DD machines are narrower and even taller than the baskets in a BD, something needed to be done to ensure that clothes would circulate. Hence the 'blender effect' you see in a DD vs. the dramatic storm going on in the water of a BD. Since Maytag went to a similar short stroke, they must have come to the same conclusion.
I think if WP were to go back to the long agitation strokes, with all else the same, the water would become more turbulent but less able to "carry" the clothes in a current from basket top to bottom.
Speed Queen still uses the nice agitation arch, but I think their tubs are wider and shallower, yes? Did Maytag's short stroke result in clothes wear? I suspect the 2.4/2.5 cu ft. large capacity Whirlpool DDs are worse with this than the 3.0/3.2 cu ft. super capacity models.
Gordon