Driving to work I take a 270 degree sweeping turn from one interstate to another. The flatness of the XJR-R1 in the turn is night and day to my XJ8. Hardly any body tilt. Don't know how much of the difference is due to the CATS and how much to rear anti-sway bar. Note, the XJ8 is a LS swap. The weight of the engine and tranny is about 160 lbs less than stock.
Is the steering rack different? Seems crisper especially at 70 mph.

 

XJR and I believe xj8 Sport get a different steering rack from the xj8/vdp

 

R may have a speed sensitive steering. R has swaybars also. Cats shocks has their own affect too.

 

Rs also, of course, have stiffer lower springs.

 

If your running OEM wheel tire combos for both models, you will get way more roll from the standard XJ8 with it's taller sidewall (225/60) and narrower 8.5" wheel which is made for comfort. Any VDP-R (mine) or XJ Sport with performance wheel and tire combo (I run 245/45 Michelin Pilot Sport SS on Penta wheels) with a much more rigid sidewall with minor roll and wider 10" wheel, the tire rides more flush with the pavement.

Those tires differences plus with whichever suspension you have make a world of difference. I also don't have a rear sway bar, I have the truss setup (#7) or as Jag calls it Bushed Differential Strut and I have CATS. I can definitely tell the difference when my CATS is on or off. Also, mine weighs 132lbs more being a VDP and 5" longer, so your 160lbs less drive line weight would make some difference. Base XJ8 3946.00 lbs, XJ8L 3988.00 lbs, VDP 4010.00 lbs, VDP-R 4079.00 lbs. The lengths of these obviously determine the turning radius, XJ8 19.80', L 20.40', VDP 20.40', VDP-R 20.40'.

 

Steering lean is something I have seen on many high end vehicles.
I suspect there is no way to have both a luxurious comfortable ride
As well as extremely responsive cornering precision.