Put shorthaul in the title so it's not confused with the mid haul aircraft.
On shorthaul I like taking a seat in the first emergency exit row, amazing legroom if I'm in economy or there's a big Club Europe cabin. It's also nice to have an extra toilet in the front (which is not on the mid haul aircraft). On mid haul I like any of the solo seats for the space offered. Even when there's two travelling if you plan to just watch TV, read or sleep then the solo seats are still worth getting.
Don't forget to update this when shorthaul gets enhanced