If you want the E+ aisle seat and can get it reimbursed, just buy it. It will give you additional PQP to help you get to Gold next year and you won't have to check the seating chart constantly starting at 24hrs out waiting for a space to open up. I spent a lot of time checking and rechecking for an E+ aisle or window to open up when I was Silver. Enjoy your free checked bag, group 2 boarding, and the priority bag tag that may or may not mean your bag comes out early.