There are differences from control zone to control zone IMHE. Solent will give you "radar control service", yet I have never had this from Bournemouth who normally leave you on your own, occasionally passing traffic info. I don't know if you tell them your routing at the initial call whether this makes a difference and then they are not required to "control" you? (i.e. from Tarrant Rushton to Hengistbury Head via the overhead)