Originally Posted by
Effinhunter
Looking over logs, I've seen the procs range for all classes from just 10 over 2 usages to 60. Hunters have a lower range of procs that can go from between 12 to as much as 35 (that's the most I've personally seen in logs). Crit rating can be highly variable if you get few procs, but for most of our recent kills, if you get 20+ hits, crit percentage has been between 25-40%.
Mages tend to get the most value out of Deadly Grace. Because of how their CDs interact, fire mage crit percentage (they gear for crit) is roughly double and they also appear to get way more procs. From looking over our mage parses, our 3 mages get between 35 and 55 procs a fight (2 potion usages) at between 65-75% crit chance. This causes a huge disparity between hunters and other classes compared to fire mages in deadly grace contribution unless you just get stupid lucky with luck streaks.
P.S. If you are looking for how many procs happened in your own logs, go to Damage Done and look at Abilities->Deadly Grace for a breakdown of your raiders.