I went Mojo. Although I'm a sucker for +spell damage. Fights don't last long enough at that level for the crit chance increase...at least that is how I justified it :).
It really depends on how badly you want the sta. If you can get by with out it the Mojo is better. Frost makes up for crit via shatter and winter's chill. So stack up on spell dmg as much as you can.