Clearances
For what it's worth - UK ATC with only one exception is the best there is. Professional, helpful, and caring (and no I am not ATC I am a pilot). The exception in 20 years or so of flying has become Essex. It is perhaps just perception but the service to GA seems to have gone down and down to the extent of perhaps being dangerous. An example - we were transitting northwards and had been kept fairly high by the last radar giving us RIS when we then had to free call Essex. No problem except that we were by then good VMC on top and we called Essex for a service - no service keep clear of controlled airspace etc. We then asked for a brief RIS to decend to VMC below. Response "I can see nothing to affect, remain clear of controlled airspace at all times"
The moral - just leave Essex alone