I unfortunately understand what Simon is talking about when he says "your lack of personality". Kady is obviously a funny and out-going girl but she is almost too serious when she performs. As we say in Newark, "girl, relax, relate, release and k.i.m. (keep it moving)
For the ebonically challenged (LOL) that means that you have to just let it go and have a good time. Let that emotion out and your performances will get better, Kady. You already have the talent, that's obvious. Now, relax, relate, release. You will not only feel the difference, but the audience will feel you. And that will shut Simon up, isn't it worth it just for that?
I'm routing for you.