[gurjeet]

IMHO, performance. Chrome's V8 engine (for running JavaScript) was way ahead of competition when it was released. It took Firefox many years to come close to it.

Disclosure: Happy Firefox user since v1. Sometimes I was jealous of Chrome's speed, sometimes I was weary of Firefox's memory leaks, but never enough to leave the flexibility and customizability the Firefox provided.

EDIT: ... and now Firefox is fast enough, and isn't a memory hog anymore, so I continue to be a very happy Firefox user.

[MBCook]

This matches my memory as well. Safari was dramatically faster but it was limited to the Mac (let’s just ignore the Windows version).

Chrome was based on Safari and was far far faster than anything else available on Windows at the time. Not only that but they moved fast and kept improving.

Firefox is great now but it took a long time to catch up.

[loudthing]

Good point. V8 gave us Node.js, right? Also I've been out of the loop for a while now about Firefox. My understanding was Firefox had a pretty bad memory leak for a long time. Was that ever resolved?

Edit: Saw your edit. Glad the firefox memory problem was resolved.