On my WAR, for merits on colibri, I have 120 DEX in my WS set for raging rush, because 120 is pretty much the cutoff point for maximum base critical hit rate (DEX - enemy's AGI) if I'm not mistaken.
However, a friend of mine mentioned (in regards to drakesbane, another critical WS) that he thought your base critical hit rate doesn't matter, and that only TP affects critical hit rate during critical weaponskills. Has there ever been testing done in this aspect? I'd hate to find out I could have swapped in STR and raw accuracy for better results all this time.