WHBM
Never flew the three as for a long time it was deemed too difficult to fly three marks but when more competent management arrived all four types were flown by the same crew.
I had migrated to the VC10 by then...one of the stories when the VC10 was flying on European routes whilst the T3s where being repaired was of a crew delaying a Frankfurt whilst catering fetched some bone china as they weren't prepared to accept the s@@t brown, handleless Bakelite mugs that BEA crews had to endure.
18 months later I was flying four different types of DC 9 without any problems..different engines..wing/fuselage incidence...loading..fuel systems and one was a freighter.
Shows what Johnny Foreigner can do ;-)