Noone can say 5% cdr is a "big" improvement to dps, especially now as we already have extra CDR from untamed strikes. But! Here's the thing... Crits turn the tides of fights! So feating into even bigger crits will improve the possibility of the crits you land to have a bigger impact than they should have.
I would not even factor critigation much into this equation.
Critigation is a rarity among non-tank classes, only 20% when maxxed Elusive, perk not slotted. Heck, many tanks don't even use Elusive, so a high critigation-chance is not something you go up against often. Mainly it's 20% and 40%, in rare cases 80%.
Anyways about WotW again I can tell an example:
1v1 bear vs. bear: first one to get a big crit will in most cases kill opponent or force our ironhide and sit on a massive advantage.
It's the same against all non-tank classes. Burst kills. You crit = opponent in trouble. Opponent easier to deal with. Big crits are more likely to happen with WotW. That's my view is on this.
I'd like to say though, that it's possible to play without crit dependency. Try to stack combatrating on as many itemslots you can afford, then use Field of War and Precise Strikes AAs. In this case I'd probably let WotW be. Stable damageoutput can be very effective too, but honestly crits or a combination of the two is favorable.