The state of LHR and the a*se ache of getting there from the South West is indeed enough for me to consider some fairly elaborate alternatives on a range of dubious carriers. If there were better (& cheaper) connecting flights from Bristol, Exeter or Southampton I would cheerfully go to my grave without ever seeing LHR again. However, my last adventure from Southampton to Brussels (with Eastern??) was an eye-watering £400 for a single buttock aisle seat and left me reassessing the evils of LHR.
It's a terrible shame, on balance I'm happy with BA. I think their product is uniformly pretty good with occasional exceptions at both ends of the quality spectrum. However, I hate LHR and LGW in pretty much equal measure.