Sorry guys, I thought long and hard about posting again but I can't leave this alone.
Thanks for all the compliments and praise, btw.
Collection, in its precisest, dressage oriented meaning, is much more than driving from the hind end. Driving from the hind end is good, but at a much lower place on the training scale than true sustained collection. Collection, in the precise, dressage meaning, *must* include lowering of the croup and increased angulation of the hind limbs, like the photo of the grey horse in the other thread on this subject.
Spyder's definition of collection (weighting all four evenly) is excellent, but its a subtle definition and hard to measure by eye. Lowering of the croup, increased angulation of the hind limbs and driving from behind is easier to discern by eye.
If you want to say that WP horses and good hunters under saddle are collected, rather than connected (the term I prefer, and that the Littaeur/Wright/Morris school of forward riding uses) just because they meet the standard of driving from behind, then you need a different term to distinguish that from a dressage horse's sustained collection as defined above.
Using the same term to describe different but equally desirable goals depending on discipline is confusing and lends more fire to the argument than it warrants.
Finally, as I was thinking about this subject as I rode this morning, I am frequently question some poster's assertions that reiners and grand prix jumpers not only "do dressage" but perform the equivelent of upper level movements in true collection. And in mulling this over, I've come to the conclusion that there are real differences, and the big one is that it is not *sustained* collection. While jumpers or reiners might need to briefly collect to execute a turn or movement, in between those movements they go in a forward, connected frame. Horses capable of suceeding at the upper levels of dressage must be able to *sustain* collection. The hallmark of a correctly trained dressage horse is that they sustain true collection and quality of movement in between the movements or "tricks."