I think you just don't know what the cycle puts you through. If you are young, chances are that they will retrieve lots of eggs. The recovery from the egg retrieval procedure is BRUTAL. Why would you want to take your body through the hormonal overdose, another procedure and another difficult retrieval AGAIN?
Plus, the youngest embryos are usually the healthiest. If you are 29 now, succeed on the first try and want to have another baby a few years down the road, whatever you make at that point will be less healthy.
So, freeze.