Lower rank doesn't equal lower quality traffic.
I have a panda hit site, due to a simple CMS error. Despite half the traffic, stats remained similar and not only that, with a bit of TLC I managed to almost double the time on site and half bounce rate to name a few.
The site has only been "fixed" for just over a month and hasn't yet bounced back but I'm confident it will.
The only real reason people dont bounce back from Panda is because they don't actually determine and address the true cause(s).