I am going off the top of my head for this, but I'm fairly certain as a tank the verdict has come down to the AP buff being superior.
As an idea of scale, a typical t8-ish geared warrior tank in raid buffs will have 28-30k armor. 1 AP per 108 armor, per pt from Armored to the Teeth for a tank with 28k armor would be 259 AP per pt!! Or 778 AP for 3 pts in the talent. That will outstrip 1% crit per point pretty handily.