Here are the raw figures for the new Jag XKR: the all-new 5.0-litre engine produces 510bhp and 461lb ft. There are also alterations to the dampers (they're now constantly variable), and the same trick diff you get at the back of the XFR appears here.
What those stats don't do justice to is the way this new engine has moved the XKR on. It sounds more powerful (the exhaust note is spot on for volume), feels more up for a fast drive. Not that the XFR suffers from a lack of poke, but the XKR - with the same engine as the XF - seems to be slightly more eager to get to wherever you're going. In point of fact, it's only a tenth quicker than the saloon to 60mph.
It also feels slightly sharper to drive. The brakes are still a bit soft for my liking, but the way the XKR turns into a corner is seriously accurate. What you do is rewarded by the car following suit exactly, which means that it's an encouraging process. No hairy moments here.
Other alterations to the exterior and interior are pretty minor. You now get Jag's weird take on the gearlever, which at least looks more modern than the old ‘J' stick. But really it's all about that engine.