I was on the BA116 (747 from JFK
The Captain made a good call and we went to Shannon, near enough in and out so we only picked up a 2hr arrival delay.
Biggest complant was a 15min handling delay at LHR
whole they waited to find steps and then busses, BA
should really have brought in more staff to speed up the process and BAA need to sort out passport control (for non-EC nationals)