Setups for dump pouches are the kind of things that you gotta try yourself. I run an SOE SMP as a drop leg (several of my teammates do, too), but my teammate Beefy hates it that way, and runs it basically as a hip pouch. I find that way, way to high to put mags in comfortably.
Eagle is really good gear. It is, however, a fairly floppy pouch, as is the Maxpedition R-P. The SOE is far more rigid than both. It'll still flexible, but holds shape better than most. In terms of which to go with, go with what appeals to you, and stick with a quality maker. If it doesn't fit your needs, trade it or sell it on Ebay and try again.
