Heathrow ATC would have to be, without a shadow of a doubt, the best ATC I've ever come across. In all the time I've been operating into Heathrow, I've only ever had one occasion where I might have said they weren't running at 101%. (I'm sure there's a 'B' team in every operation.)
I've been lucky, and never had to go around there yet, but on more than one occasion I've suggested to my FO that he might like to mentally re-acquaint himself with the go around procedure as we've got very close to the ground with another aircraft still on the runway.
In my experience, the controller is rarely the one who should take most of the blame when such a traffic-related go around occurs. It's usually a pilot who's a bit tardy clearing the runway or who's not followed ATC speed control instructions on finals. (I don't know how many times I've found myself at 160K as instructed and gaining quite markedly on the aircraft ahead who's also been asked to maintain 160 k to 4 DME.)
My only complaint is a minor one. I usually operate a 777-300 into Heathrow, and at the weights we're normally at, the request for 160 knots as early as it usually comes involves our lowering gear to allow us to take 30 flap, (flap 20 speed is usually somewhere towards the high 160s). This involves lots of power (and I suspect more noise for the people below) than we'd need if we could remain just that little bit faster down to around 2000'. I think most would agree that that's small cheese as far as a complaint is concerned, and I accept that the controllers have come up with a speed profile that suits the majority of the many types that operate into Heathrow rather than just the triple7-300.
I know it might be comparing apples and oranges, but I've often thought it's a shame the YSSY controllers couldn't spend a couple of days watching the way the Heathrow controllers handle their traffic.