I went the other way. Having done a 3 year ATCO Cadet course with NATS, my final posting was to a MOD(PE) unit with military aircraft, procedures and aircrew where I had to quickly learn all the subtle differences eg PAR, 1/2 mile SRA's not using continuous talkdown, autonomous airway penetrations etc. This I found was no problem because the three 3 year course (including a 9 month stint at a JATCRU) had prepared me to expect anything so I could readily adapt.