The US and UK higher education systems/styles are very different

Y will be an easier and better fit - academically, socially and culturally  (for US kids)

The one advantage of the  UK system is that you will  graduate in 3 years.

But you can quite easily do this at Y as well. Buy why the rush? I would spend full 4 years to have the best time of life.

Y is a lot more flexible in customizing an education for you.

So the answer is actually quite clear, if not a no-brainer.