In general, crit is more valuable than haste, so players should hit the lowest breakpoint feasible. Players should jump to the next breakpoint only when they are unavoidably about 1800 rating below the next breakpoint. In other words, you only want to drop a maximum of about 1800 crit rating for it to be worth jumping to a new haste breakpoint. On the chart above, the important breakpoints are the ones for ReM and EM breakpoints close to them. However, 25-man MWers will likely not find themselves using EM often enough to warrant gearing for its breakpoints. 10-man raiders may jump to an EM breakpoint if they find themselves using it often, though it is preference. Thus the important breakpoints are:
With 5% Haste Raid Buff:
1) 3145
2) 6141
3) 9158
3.5) 9916 (viable 10m only EM breakpoint)
4) 12154 (NOT 12138*)
Without 5% Haste Raid Buff:
1) 4719
2) 7864
3) 11033
3.5) 11828 (viable 10m only EM breakpoint)
4) 14178 (NOT 14162*)
*This is due to a weird interaction with a Soothing Mist pseudo-breakpoint being near a ReM breakpoint. The theorycrafting discussion behind this can be found
here.
-It could also be noted that Haste is a very weak Mana Regen stat in 5.4, affecting pretty much only Horridon’s Last Gasp and some other RPPM trinkets (the rest of which I believe are throughput), to clear up any misinformation regarding the RPPM change.