* An article written by a fellow mozillian: Android/ARM Firefox Performance: where we are and where to go
(on a similar topic)
Also in terms of crashing, sometimes the chipset makes a difference:
Some of the crashes that are happening for Fennec have occurred on devices that have the ARM Neon multimedia extension. Samsung Hummingbird SoC debuted on the Galaxy S.
Tegra 2, does not have neon, however the Tegra 3 series will (http://en.wikipedia.org/wiki/Nvidia_Tegra ).