Or, put more precisely, bulkhead aisle or exit row middle?

I'm torn. For my frequent transcons, this summer my favored exit row aisle seats are rarely available, and my second favorite exit row window are rare, too. I'm 6'4" with broad shoulders. So I prefer an aisle or window so I can not be folded side-to-side like a taco into my coach seat.

I can get either an exit row middle (more leg room, less shoulder room) or a bulkhead aisle (less leg room, more shoulder room) on an upcoming flight. I haven't taken the bulkhead seat in an -800 ever, though I know it has a curtain and room under the last row of first. In the middle of the exit row, one hopes for seatmates who are of average size or less.

Any advice from those who've been in a similar spot?