The memory leaking is a legit issue. I've noticed the same thing. I can close a bunch of tabs and the memory usage will go down but not by anywhere near appro

The memory leaking is a legit issue. I've noticed the same thing. I can close a bunch of tabs and the memory usage will go down but not by anywhere near appropriate. After a long while (days), having just a small handful of tabs open will show a significant memory usage. At that point, the only solution is to close the browser and re-open it. The problem seems to be mitigated in part by using private browsing mode. It doesn't really solve the problem but if I know I'm going to be browsing script heavy sites or opening a ton of tabs for research or something, I'll open up private browsing. When I'm done, I close that private browsing window and the memory is completely released because Firefox walls off everything in private mode.