To reach 4718 haste in my current gear I have to drop a lot of crit. The extra tick from ReM with that haste will obviously be better.
The HPS difference between 2k more haste in favour of 2k crit is very marginal. On top of that, crit helps with mana management.
So until I get gear which will take me closer to the haste breakpoints without reforging, I'm sticking to crit.