When I'm travelling on Southern and most seats are taken, I prefer to sit on the metal luggage rack than the middle seat. It's more spacious and not exactly that much less comfortable than the other seats in my opinion.
When I used to commute in the peaks to London (in the days of the VEPs) I always opted to stand in preference to sitting in the middle seat of 3. I wasn't the only one. There wasnt any "stand in the vestibule" option on those trains, of course!
As to 442s vs 450s I remember being pretty annoyed when my usual train home (17:48 Waterloo - Southampton) was changed from 10x442 to 8x450. I appreciate if we're talking 12x450 to 10x444/442 then it's perhaps a little different, but I would personally prefer the 444/442 option over 450s because if you do manage to get a seat at least it will be comfortable.
