Verse > crit.
Verse gives you straight up damage increase (the damage reduction is a bonus, but not really why rogues take verse). Crit is 150% in pvp, so its not as amazing, but its still better than haste for rogues - especially given that we want short burst damage.
Basically, would you take crit over AP/agi? Probably not, as you're losing a direct increase to your damage. The same logic applies for verse.