A 35% boost to speed is enough to invest 5 points into cat form in my opinion, and a 20s increase to duration ontop of it is just stellar.
the T3 needs a rework though, that is for sure.
Stamina resets to 3 when you leave Ava no matter the previous state.
Here is video proof
This might be a feature
I did not see it talked about as a feature
if you want to add this as a feature and an alternate use of ava, probably make it more clear.
Another reason to make it be headshot is what you just said, the characters that take high velocity mag dont even use headhunter. So the item costs 500 more when most characters that take the thing that makes it cost 500 less dont want it.
Velocity is kinda in the meta right now, so changing it woldnt be the worst idea.
Or they could make it so you need headshot booster or high velocity mag, so its like you have 2 paths for headhunter