Welcome to the club, Kevin.
I have had my s type Diesel for 7 years and it has treated me rather well.
I find that it is quite fast and quite economic. I have not even thought about remapping. A friend of mine [many years ago] had a remap and managed to blow the engine to scrap when showing off. For that reason, I have found that the performance for my well looked after Jaguar is just as it left the factory.
But it is your choice. Some have some have not,
Regards,
Peter.