I originally went for the "one ski quiver" back in 06. I got PE's and thought they were awesome. In 08 I got some invaders to be park specific, and left the PE's to do the rest. Then this season I got some bacons to be my pow/everything but park skis. By now my PE's are in rock ski condition, so it makes a perfect quiver.
Basically, one ski quiver works well, but more than that is the best. I'm not really abusive on my skis, so I never had to get 2 pairs in one season.
There are better one ski quivers now though than the PEs were.