Good morning JoeO -a few thoughts to consider,
My mistake #1 - bought summer ultra performance tires, on my ‘05 (Bridgestone Pole Position). So depending where you live (I’m in San Francisco Bay Area), ambient temperature turned out to be an issue. According to Bridgestone, they don’t recommend driving the car bellow 45f or so, we, it gets below that here - so those were not ideal in my case.

When new tires went on the ‘04, I selected Michelin Pilot Sport AS ultra performance tires, and they’re great. No temperature concerns, really quiet, and with tons of grip! Tread rating was higher than the Bridgestones, with A/AA traction and temperature ratings. With the XF’s staggered tire size, rotation is NOT an option, so I suggest sticking to major tire series as you may purchase two tires at a time.

some pics: you can see the tire pattern diff between both tires. Let me know if I can add anything else, and welcome to the forum!,,