On short haul, it's always best to go with an LCC or even main line, than to use Miles on a main line
Not really PaxBoy. Replace "always" with "very often", if you wish.
I have just done recently:
- LGW-VRN (BA)
- LHR-CDG-LHR (BA)
- LHR-AMS (KLM)
I used the miles and the cost were less than both LCC and legacy.
As Fincastle wrote, you have to plan well ahead.
Ciao
Ulxima