Steamchicken
T5 is not an upgrade in the sense you state - it is a totally new 'product'.
It has not been handled well - possibly because the management at BA have over the past few years, whittled away the infrastructure, leaving a shell of what was once a Great British company.
BA is no longer the 'Worlds Favourite Airline' - its service provision is generally poor, mostly due to mis-management, and partly due to the attitude of a select few who believe that the name BA overrides any deficiencies.
I truly feel sorry for the many good people who work for BA - they are getting the brunt of the reaction from a public who are still deluded enough to think that as BA is our national flag carrier, it must therefore be the best.
A sad and huge mistake; caused not by the ordinary worker, but by inept management and poor investment.