In general, only newly qualified trainees without previous type on their licence will have to do base training, all others qualify in the sim and the first time they handle the aircraft will be with passengers on board. The 2 fleets that the base training is still required on are the Airbus A319/320 and the B737. The Airbus base training seems to favour Chateauroux in France for some reason, the B737 I don't know. In the past Shannon and Prestwick have been used.