Finally switched off the stock blades on the pro today to the plasti blades. Seems to fly about the same to me. I'm still learning to fly and can hover fine and am starting to fly around a bit more. Flat bottom blades didn't seem noticeably more stable that the stock blades to me. Just my .02.

They're great blades, though. With a minor crash and nick, 10 seconds of filing, and you're good to go.