Instead of saying "You can use improvement", why don't you actually suggest where the improvement could be directed?
I think it's a very good trick - work on your patter, although it only needs a little touching up.
Also, the handling is a bit funky at times, such as when you're pick up "the kings" from the table.
Also, what's the purpose in making both of the kings "disappear" to make the ace appear between them? I'm not saying you should remove this part of the trick, but maybe change your patter... Off the top of my head, I'm thinking something like "Now, the Kings are going to leave to find the [selected card], watch closely as the first one locates it, and the second one leaves to trap it."
Great job,
Ben
