I have many hundreds of hours IFR in Los Angeles airspace and consider myself very familiar, knowing all the VOR's and airways. Despite that I occasionally encounter controllers which are neither pleasant nor helpful. They give you "impossible" clearances, sometimes treat you as VFR when, in fact, you are IFR or vector you well above the glideslope. I remember one particular instance at Van Nuys where we just couldn't get established in time (poor vector, tailwind, steep G/S), executing missed approach to be told "IFR missed approaches are not allowed"
My point is, without giving you any explanation of the UK ATS system, there are good controllers and not so good controllers.