Ian Callum had a big job on his hands when he was asked to take over the job of Design Director after the death of Geoff Lawson. While he was and still is an admirer of the S Type quite a few people did not like the retro design and some did not think that the S Type was suitable for a medium sized luxury car. There is much in the XF from the S Type apart from engines --- the steering, the brakes, and the suspension, all of which are well tested. The mesh radiator grill on the face lifted s type is now common on all Jaguars. Ian Callum did listen to comment, and while there is some opinion of the exterior design of the XF, it has proved to be a good base for the SUV which again was built for those who wanted that type of car.
If you do look at the XF, and its smaller and larger family, and you make a comparison with the S Type, you will see that theXF carries some of the characteristics, with the main one being the atmosphere. The XF certainly has that!
Regards,
Peter.