UPDATE: it appears that Firefox 60 has changed/removed this setting, unfortunately. I don’t know what these people are thinking, and how the smaller “top site” icons are supposed to be any helpful, but either way, the option to return to the old look with the larger icons is gone, apparently.
There is a setting browser.newtabpage.activity-stream.topSitesRows though, and I’ve changed mine to four (the default settings only allow one or two rows – completely idiotic) to make the best of a bad design decision.
Original post below.
If you’re like me, using Firefox’s “New Tab” page like a speed dial for your most common sites, then the update to Firefox 57 “Quantum” left you rather miffed – the most frequently used sites are rendered in tiny thumbnails (hey, I’m not getting any younger…), and even when you disable the “activity stream” nonsense, they’re not getting bigger. I really like the speed of FF 57, but that’s really one annoying new feature.
Thankfully, there’s an easy fix, namely typing about:config into the address bar, searching for browser.newtabpage.activity-stream.enabled and setting it to “false” – hey presto, the old New Tab look is back. Phew!