Anything but the KC135!!
A chorus of agreement there I'd say from across the RAF. The boom was a nightmare on anything but the smoothest of days and I vividly remember my probe tip disappearing up over the intake on thankfully only one occasion. As well as the helpful boom operator, the crew sometimes had a nasty habit of finessing their nav up the towline; with the length of the extended boom any roll was alarmingly amplified!!
The brief for a first stab against a 135 was like a horror movie. How the solid 'basket' could break the canopy or nosecone, how the hose could snap off and end up dangling down the engine intake , etc..... Not surprising then that we were all a little reticent when the Tri* cancelled.
I'd take any drogue over that thing any day: VC10, Tri*, KC10 wing and C/L, Herc wing and C/L to name all the ones I saw.
Twos up on a Canadian KC130's wing hoses was a bit hairy too. If your backseater tells you not to look at something, it's for a good reason!