As you have gathered, it is pretty random really. Some airfields treat you exactly the same as a plank and insist on you following all plank procedures. Many moons ago, I recall being forced to fly a full circuit to join together with a couple of 737s up my chuff at a regional "international" airport, which only had one runway.
I've no objections to flying any pattern provided they don't try to send me off into IMC for the ILS after holding me outside for twenty minutes after asking for a VFR join (think fuel reserves here, ATCOs)... but there's no pleasing some. Whilst being vectored in to an international airport for the ILS under IFR I was told to expedite my ILS due to following jet traffic. So I did.
Next thing, they directed me to slow down for spacing as I was catching up the Boeing airliner ahead.
