Performance is ok but it isn't my main concern, i'm also concerned about features (after all lynx is faster than both of those browsers, yet it lacks a bit on the features side).

In any case, this isn't a hill i care to die on. I just do not see much of a difference between the two browsers anymore in terms of what they can do. I used to like Mozilla for its features (in fact i was really annoyed that they switched their focus to Firefox back in the day and left what they renamed to "Mozilla Suite" to die) and Firefox later for its (remaining) features. Funny enough now that i think about it, the reason was also "performance" back then and again i didn't care about it but i did care about the features lost.

I guess they kept on the same path and eventually Firefox will be a chromeless, featureless HTML terminal - not very useful as a browser, but it'll be the fastest HTML terminal :-P.