The classic version was one of the best Firefox addon. It used to display several pages within the same Firefox window with no space wasted and the layout you wanted. Now every page contains a full Firefox window which is a huge waste of space! That's not the fault of the devs though! But the limitations of web-extensions and Firefox 57 removing the technology they used in the classic version. To me it was THE functionality Chrome did not have.

I give it 5 star because the devs made an amazing job, they're not to blame.