On all of my E-175 flights, I have been in F, so I cannot say anything about Y. I find that the A side is the best in F because there is only one seat on that side. You have both an aisle and a window, which I love. Seat 2A or 3A is best. I would take 4A before 1A, but I would take 1A last. Any aisle seat on the side with two seats in a row in F are fine except the bulkhead. This is all based on my travels in the E-175 in F on more than 25 flights.