Solent are notorious - I flew out of Bournemouth a lot, which adjoins Solent airspace to the West. Several times, I was told to 'Standby' for up to 30 mins to wait to even talk to them about entering their zone!
Many's the time I just gave up, routed to the West / North / East of their zone and just totally bypassed them - much quicker!! Bournemouth, which is (in terms of movements, including heavies, bizjets, twins, SEPs) I believe much busier than Solent, is an absolute pussy cat to deal with. Some times they'll decline to let you into the circuit (which is fair if there are about 8 of you on touch and goes!!), but they'll always try to accommodate.