Surely a 1 hour drive from the Londonderry area,parking up at Bfs and taking the direct 1 hour 10 minute easyJet flight is the less hassle free option,and cheaper too
Taking an example,
LDY-(MAN)-CDG on Friday 10th June back Mon 13th June is £114.
BFS-CDG return on same dates is £124.
Derry to LDY is £25 return in a taxi (or free if a friend or relative leaves you), Derry to BFS is at least £25 return in petrol (leaving aside additional mileage on car). But then you have 3 days parking at £21 in long stay car park.
Both flights arrive at 17:35, the LDY flight leaving at 12:50, the BFS flight leaving at 14:50.
But it takes 10 mins to get to LDY and 1 hour and 20 mins to get to BFS, then you need time to park, etc. BFS being larger, you also need more time to get through the terminal. LDY: leave the house at 12:00, arrive airport 12:10, 40 mins in terminal. BFS: leave house at 12:30, hope the traffic isn't bad, arrive airport at 13:50, park car, get into terminal 14:00, 50 mins at terminal.
There's not much of a difference, BFS perhaps shades it on time, LDY in this example working out £61 (or £86 if you get a lift) cheaper for a family of 4, other days the price differential may be reversed.
I suppose it all depends whether you prefer driving or being flown.