I'm not sure which builds you compared. Firefox 22 is currently in Aurora phase, and Firefox 21 is Beta. It does seem like there's been a regression in the ag

I'm not sure which builds you compared. Firefox 22 is currently in Aurora phase, and Firefox 21 is Beta. It does seem like there's been a regression in the aggregate scores. Thanks for bringing it up, though, that should be looked into. Have you submitted this regression to bugzilla.mozilla.org? If not, I'll create one for it to be looked into. Just for kicks I ran can-attribs on a pre-Baseline and post-Baseline build of firefox nightly on my macbook, and the scores received a modest (about 2-3% average) bump from the landing.