I love the ponchos. I don't like getting wet, even on the water rides. Only if it's a water park do I tolerate it!
But I'm opposite of others, I don't do the dollar store ponchos anymore. I did for September, but then you can't fold them back up and re-use them (well, I couldn't), so they get tossed and the idea of all those ponchos being tossed kinda made me ill. So we each now have one Disney Resort poncho (something like 7.50 each, I think), and they are thick enough that they can easily be re-folded, even when wet. I've used mine enough that I'm just about to the break-even point compared to if I had used one dollar store poncho each time.
Everyone laughs at the ponchos before the ride...then after most people look miserable and tell the poncho people they wished they had thought of it! Love the poncho!