I've been a loyal Firefox user for almost as long as Firefox has existed. So I'm probably a bit biased. However, when I used other browsers, and if it wes just to try them out, I didn't notice any benefits in terms of loading websites and executing their scripts. This includes Chrome. In benchmarks there are obviously differences visible, but to me as a user they didn't matter. I wasn't so short on time that I needed those microseconds. So I really don't get how performance could be an argument in this.