I barely do because they are hardly even worth it. If you don't land a precession hit with the throwing knife, it's doing jack nothing. But even if you do land a precession hit with it, it's still a disappointing amount of dmg. I could do about the same amount of dmg with two precession shots with a hand cannon for example, which are much easier to land than with an arcing throwing knife. The only time I see any use for the throwing knife is when you're in desperation mode, like when you are on low health and forced to reload your weapon. It's just weak sauce, at least in PvE. And the new exotic armor piece that allows you to have two charges of it doesn't make it any more worthwhile either. Then we have the dodge ability. While more worthwhile than the throwing knife, it still feels kind of weak sauce to me. The reload effect is nice and all, but there are a lot of times where I would not want to have my character step backwards and perhaps fall off a platform or something, like when you are standing on Calus plates for example. I feel like playing a character with abilities that were solely designed with PvP in mind.