The Vulcan was a brilliant tanker - I remember being told that the rabbit hutch round the HDU meant that the trade of aircraft carpenter had been reactivated! The other benefit was that the Vulcan crews had clearly missed out on the Victor OCU training on how to find alto/cirro-stratus to hide in, useful angles of bank for inducing the leans, and 10 infallible methods for dropping the chicks at the furthest end of the towline while pointing in the opposite direction to that requested....
C130 was probably the easiest in the F4, especially at low level. Does anyone else recall the "If you get behind me you can have some gas" affil in the FI, before plugging in at 1000ft?
Agree with Beags though - the Q-fit F4 v KC-135/BDA at FL30O was definitely in the 'demanding' category.