The new CarMD data is out, I can't see much that is XF specific but their information states that the model is in the top 20% of most reliable cars. They provide repair frequency and cost for the top 5 most common issues, these are across the Jaguar model range, that makes for about 40% of all repairs. They're much like all the the other automakers except for some of the others requiring expensive ABS control module and ignition module repairs:

Rank Repair Labor Parts Total Repair Cost (Parts & Labor) % Jaguar repairs Sept. 1, 2011 - Sept. 1, 2012
1 Replace Ignition Coil(s) and Spark Plug(s) $192.91 $290.54 $483.45 12.50%
2 Replace Oxygen Sensor(s) (O2S) $95.98 $312.27 $408.25 8.88%
3 Replace Catalytic Converter(s) with new OE Catalytic Converter(s) $158.97 $1,267.23 $1,426.20 8.55%
4 Replace Ignition Coil(s) $121.36 $117.12 $238.48 6.58%
5 Replace Positive Crankcase Ventilation (PCV) Tube $304.36 $56.46 $360.82 6.25%

So...the expensive one is Catalytic converter replacement, does anyone have any experience with this? I'm guessing this is a high mileage issue?

Have a look for yourself:
2012 Manufacturer & Vehicle Rankings
www.carmd.com/scorecard