Chrome's memory usage is[1] (and always has been[2]) very high and has been steadily getting worse where Firefox has been getting better and better thanks to the memshrink project[3]
I don't care about memory, i have 8GB and i am not somebody who has 500 tabs open. What i care about is independent processes. When a site freezes the rest is unaffected. The same with Icognito Mode, this is a total joke on Firefox.
What counts in the end is speed, security and api's.
Anecdotal evidence, but over the last month I've seen Chrome not work on a few websites (broken js) and have seen the crashes due to flash a few times too. Recent changes have not been for the better.
I've recently switched back to FF and found that it worked in the places that Chrome didn't.