Tuesday I dived in a single tank wing.
Thursday I dived in a bc.
Fortnight ago I dived in a twinset.
Bloody brilliant in all of them, me
All of the really good divers I know could dive a plastic bag full of air and a hose pipe. Throw anything at them and they're superbly competent. You never hear them whining about a buckle for 25 pages on the Internetty.