I've used them in the past, and prefer the double-leg style, as single kickstands generally do not offer sufficient stability with loaded panniers (YMMV).
My present commuter is my son's 29er, which does not have a kickstand. I have no issues with leaning the bike on one pannier or the other (such as against a fence or post, tree, etc), or by wedging/leaning the rear wheel.

My new commuter will not have one, but I plan to have one of those segmented (like a tent pole) seatpost stands handy for my longer adventures with loads.