These graphs are taken from http://phonedash.mozilla.org.  Browser startup performance is measured on real phones (a variety of popular devices).

Time to throbber start seems steady this month.

throbberstart

Time to throbber stop has multiple small improvements.

throbberstop

Eideticker

These graphs are taken from http://eideticker.mozilla.org. Eideticker is a performance harness that measures user perceived performance of web browsers by video capturing them in action and subsequently running image analysis on the raw result.

More info at: https://wiki.mozilla.org/Project_Eideticker

eide1

eide2

eide3

eide4

Those all look pretty steady to me, but there’s lots more to explore — be sure to check out eideticker for yourself!