Being a retired ATCO who now does AFIS and A/G, I sometimes have to stop and think what to say on A/G. I've heard some A/G operators say 'at your discretion' to a pilot advising he was taking off or landing, while I heard a report from a Blackbushe pilot a couple of weeks ago (also ATCO Retd) where the 'Blackbushe Radio' operator (normally 'information') instructed him to 'hold position' when he advised he was lining up because another aircraft had just landed and had not yet vacated the runway.
I occasionally had cause to phone Stapleford Radio when I was controlling on Farnborough LARS North and the person who answered always sounded professional, mind you this was over 5 years ago. And bear in mind it can potentially get very busy in the Stapleford circuit with Kingairs flashing about and simulated IF training in progress.
Also bear in mind when a person passes the exams for an ROCC (Radio Operators Certificate of Competence) and it has been signed by the radio station licence holder, there is no machinery for periodically checking the ROCC holder's competence as there is with civil and military ATCOs and FISOs.