Blood War Profiteer
Couldn't be any worse than Elves overshadowing other racial choices then.Theoretically, you could get Elven Accuracy on a Champion Rogue for a 38.6% chance to crit. So the crit feature is giving you another 24% chance or so to crit (the base chance to crit with Elven Accuracy is 14.3%).
24% chance to do 35 more damage (at max level) is about a 8.7 DPR increase. It's in a weird position where it certainly isn't game breaking but is enough that it might overshadow other possible subclass choices for Rogues, specifically.