On my xubuntu laptop, I observe the opposite. Firefox leaks memory until I need to restart it, several times a day. However, Chrome reliably releases memory, and I never need to restart it.
On my Arch laptop, it's exactly the opposite - Chrome can become supper sluggish even as I have 16GB of RAM, while Firefox stays snappy.
I assume there are more factors that go into this than just the browser itself. For example, I find Ubuntu to be one of the more sluggish distros out there in general, while Fedora and Arch feel way snappier, but am sure this isn't the case for everyone.
