Jaguar engines 2.5L and 2.7D respectively

Hello community, plan to buy me a Jaguar S-Type with a 2.5 L petrol or 2.7L diesel soon. Who has experience with these engines? Had already an S-Type with the 3.0L V6 and was very satisfied. Is the 2.5L also as reliable as the 3.0L or is it more prone to repair? What about the 2.7L diesel engine? Does anyone know from whom the automatic transmissions come from Jaguar, who is the supplier? Obviously, the automatic transmission is not as reliable as the V6 3.0L engine. Each message is gratefully noted. Greetings, Jagfan