OK, here's the deal. If you want an aisle exit-row seat, go with 9D. 9E is fine, too, because there is no 9F. The FA will typically allow you to put your bag under the seat in front of you. (My gf and I have been allowed this every time we've taken 9D and 9E.) This is a superior outcome to 10C, a nearby aisle seat which is also an exit row -- but with no storage in front.
For a window aisle seat, go with 10A or 10F. You'll get no storage in front for either seat. You can get out of 10F to use the lav by walking forward and passing in front of the pax in 9D and 9E. 10F is kinda fun since you often get to sit next to those newbie Preferreds who did not do any research and booked 10D and 10E (technically exit-row seats) -- but the pax soon discover that those seats are no better than a typical coach seat on the A321.
