@Whitey - I agree but what about domains/brands that are generic search terms as well? Perhaps the variance was so low it didn't matter.
I think UX/UI is one of the major Panda factors. Chrome has enough market share, that they can get rely on the data it creates, and we can only begin to speculate one what it might be reporting. The fact is that we know they are, and so why wouldn't they use that data to improve their index? Of course they do.
So I am not even sure if there are any on page factors for Panda, although indirectly they may result in lower Panda scores, e.g. lots of ads, or poorly written weak content may result in less time spent on site, more clickbacks, etc, and thus effect Panda score.