I usually go w/ the Orch no matter what.
But Y is the last row (some wheelchair seats behind Y).
A lot of people prefer the mid-balcony because it is wide open, as opposed to the low ceiling in the rear orch.
Distance-wise, you're closer in the Orch; but viewing and feel may be better in CC (triple-digits are the center ones).
Sound-wise, it really can differ depending on the show, its equipment and techncians.
Remember that the mid-balc CC is behind an aisle, behind the front part of the balcony, the suites, so it's important to know that CC is not third row of balcony section.
If you're the type to try to sneak up front (hopefully not rudely and not interfering with people who have legitimate seats!), then the Row Y is better, obv. cause you're already downstairs.
Gotta check out the Warner, no matter what seat!