in many cases I've found that during EX primals my GL goes off or stays on depending on the last second. so having skill speed in fights where you move a lot is quite helpful. I even switch to fists of the wind just to get to hit the next target faster.
in mostly static fights TP is a huge issue so stacking DET or CRT should be the way to go. due to the nerf to cross classed b4b and ir I'm of the opinion that mnks should stack DET while DRG should stack CRT. but that's just me.