If you have any concerns about punctuality, then flying Eazyjet makes sense, particularly if you can access Gatwick, and particularly on Domestic sectors, which are the first to get binned by BA when there are problems.
Cityflyer stopping ABZ flights was bad news for me and my BAEC tier points.
Pre-purchase of an over wing exit seat on EZY secures leg-room AND priority boarding... And a choice of hot (ok warm) catering if required on board.
The paid lounge at Gatwick is way ahead of GC at T5