London ATC have always sounded like they had their heads in a bucket of cotton wool. You turn the volume up to hear them then get deafened by the next aircraft to transmit. Scottish on the other hand are crisp and sharp...must be the whiskey! Hoped for 21st century comms with the new centre, but it is just the same.
We have a $180m wonderjet with the cheapest headsets on the market, expect London ATC have the same.