1. YouTube video lags too much (which less happened in Microsoft edge) My machine is dual core & 4gb ram with a igpu called intel Q45/Q43 but i think 720p should be not lagging in this pc. I always can switch browser but i love fire fox syncing thing that's why im trying not to shift. But, if Mozilla won't fix my problem then i had to shift it. some days ago like 6months ago or long ago mozilla fixed firefox video playback by a update and it was really great and worked for me. 720p was working really fine. but now on recent update... it really lags too much. 2. fire fox becoming heavy, we all know chrome is memory hungry and uses very much ram, but i compared firefox to chrome before it was true firefox used less ram then chrome. but nowadays firefox uses much ram then chrome which is really wierd so fix it aswell. 3.some times facebook photos do not show and shows a text" a man standing with an umbrella" 4. please more optimize for a low end pc bcz I & many other people can't even afford mid sepc PC. I loved firefox for a long, i don't want to leave it! So, please Mozilla fix my problem. ._.