Correct - later flight is 3 class so therefore has AVOD as opposed to 12 channel system.

Meal service is the same on both. Remember BA classifies this as a leisure route, so therefore you'll have 2 bar service runs before you even get a sniff of a meal tray.

The inbound later flight also has the advantage that it operates during sleeping hours, whereas the earlier flight leaves 4.45 (ish) which is still pretty early during the day and you land at LGW middle of the night in the old time zone.