While we're on the subject of RT I have to say I like the American way of communicating in the circuit by prefacing their calls with the aircraft type and then call-sign e.g. 'Cessna 172 G-ABCD (N123) left base 21'. This gives you a clue as to what to look for and some idea of the likely speed. I know this probably takes a millisecond more of air time and also requires some knowledge of aircraft types; but I like it!