Amusing. I remember when Chrome first launched its claim to fame was being super fast. Of course now everybody uses it, and that somehow made websites think it's okay to add megabytes of slow tracking JavaScript so pages load slowly again.
Good to see Firefox is making strides in that direction.
Personally I would love to see Google penalize websites that have too much JavaScript and search results. A web page should be clean and efficient and render quickly, if it does not then it is less useful and should be further down.
Except on Google maps. I suspect Google to actively trying to sabotage Firefox there by using obscure elements which are particularly slow there. It's very hard to prove though, but I've had success once by faking the user agent, then it was fast again. Didn't try recently though.