I'm experiencing significant lag when scrolling on Firefox Mobile, the frame rate can seem significantly lower than, for example, Google Chrome. It's difficult to articulate the problem because there is simply a general lag, a lack of "smoothness". It seems more pronounced scrolling through pages with more images, and scrolling often seems to stall when scrolling over images, then speed up slightly over text. Other elements such as horizontal scrolling Nav-bars have the same issue.

I'm using a Nexus 6, stock Android