I saved £35 thanks very much True. Like using Ryanair, if you know what you're doing, you can actually get cheap train tickets in the UK.
Time-wise it will more likely than not prove quicker than flying to Aldergrove.
And yeah, I'd rather get a train to BHX, which takes about 2.5 hours, then get home in about 5 minutes from LDY, than spend 1.5 hours travelling to BRS, flying to BFS, then spending anything up to 3 hours getting home. Also, I will support my local airport when I can, which I am sure you do when you travel back to NI.