The LGW-SSH will be standard mid haul BA service.
Complimentary drinks and a full meal service....i.e not the all day deli.
Entertainment is via screens which are situated on the overhead panels with about 12 screens on the whole aircraft. There will be 1 film and comedy programmes on each sector.
The aircraft should be a A321 (although not certain as i am MAN based) and therefore does not have overwing exits.
As for going charter.......the level of comfort with GB will be a world apart.