I wouldn't go so far as to say Kat is OP but laning against her is a chore to the extreme. Constantly keeping track of her teleport is painful, and if she gets ahead, she can chase anyone down with it.
What I would suggest to make laning phase a little less obnoxious would be to lower the range of her damage when she picks up her knifes. That way I wouldn't have to run to the over side of the lane everytime her knife lands somewhere.
Anyone else think Kat is overly annoying to deal with?