I leveled engineering for the pyro rockets and decided to get these too since I like crit. I have to say some of my greatest moments in wow and world pvp are when these babies malfunction. I say 3/5 times all work, 1/5 one will lag behind. 1/5 as you're pursuing a very important target, your main and only your main's will launch you in the air, rendering your target safely away by the time you land. Although this sucks, it is so funny because of the frustration it causes to you and relief to your target.