The question is, where would you put the thing, even if it were allowed? You can't sit in the exit rows (too cold for the baby anyway to put it there).

If you opt for a lap baby, then you'll have him on your lap. The bulkhead rows wont have any room for any contraption but at least you can get in and out of them more easily. You also wont disturb those in front of you. Try to get one, although those with smaller babies will be priority.