I'm only a small fish, but in the last 12 months I've had 131 Business Class flights.
Of these, 2 were unfortunately via LHR. What an expensive, squalid dump that place is. And as for the immigration queues...
At least I wasn't flying ba, so arrival on stand after half an hour or so's holding over LAM wasn't delayed even further on the way home.
In my job as an aviation consultant, I have only 2 travel stipulations:
1. No flying to/from LHR unless there is no feasible alternative.
2. No flying with ba. EVER.