Originally Posted by LHR/MEL/Europe FF

I would suggest neither! While YMMV, I would wholly recommend two window seats. This way you each get a nice view, don't have any neighbours, and can control the windows.

The middle seats aren't that conducive to chatting - they have to be moved forward. I can't see any advantages of taking the middle seats (unless there is a medical or care-giving reason to do so). The middle seats look less spacious, less private, and have no view.