How about we agree to stick a 'Civil' in front of 'Earth Station'?
Then I can retire to bed mulling over the question of whether 45 cm 'counts' if it has a specialist role (Its used for tests for Inmarsat)
If we are going to count the number of 'big' dishes then thing could get very silly very quickly. I make it 13 dishes large enough to be individually marked on the site map.
Its certainly the oldest in the UK, the first to receive transatlantic Comsat traffic and various other things.
Its also one of those names, like Calder Hall, Woomera, Fylingdales and Jodrall Bank, that bring to mind a particular era of rapid technological advance in the British mind. Saying 'Goonhilly' to a Brit of any reasonable age and technological savvy will instantly create images of time and place in their mind much as saying 'Muroc' would to an American of similar age and interests.
BTW, if you track directly West from the site you reach Poldhu Point, from which Marconi's men transmitted the first transatlantic radio signal.
Rick