The double wishbones front and rear should allow for softer shock rates yet still maintain the great handling. Most forget or take for granted this set up which is one of the selling features of this car to me.

Only a few cars are still using double wishbones front and rear

 

I believe Jaguar went back to front coils for reliability reasons, not for improved comfort.

 

I have an 04 XJR and just did 19 inch Verde Axis V99 wheels with 275/40's all the way around and this made the ride much nicer being the tire was slightly taller.