I've got Anemic Agility on the pistols. I just really like the potential flexibility of having a rate of fire increase come from a slot on the warframe, rather than a weapon slot. Plus, Razorwing Blitz also gives a lot of extra damage when stacked on top of Anemic Agility.
For me, however, the added speed hinders my movement and aim so much that the extra damage isn't worth it, which is a shame. Unless i stay still of course, although that's usually a good way to get killed. Dunno if anyone else can relate. Hitting 4 stacks and firing the pistols feels amazing, and i have zero problems keeping up the stacks. And, i like that something rewards you for casting your abilities. It's just a little sad that such a cool thing is so personally inconvenient that i voluntarily don't use it. Eh, maybe people like the speed and i'm just bad at flying that fast.