After 9 years with BA.(Tristar and 747-400) their employment terms meant I had to leave, so I went to Virgin on their 744 training. What a difference! Vastly better working provision but a real eye-opener as to the range of differences between externally similar aircraft types. Engines, obviously, but things like APU operating and other peripheral areas which meant a lot of re-shuffling of the memory bank! Had 3 very happy years and would have stayed longer had it not been for the knock-on effect of 9/11. Can't complain of constant employment from 17 to 66 though.