Having read comments from autox'ers on this board and results from various shootouts the XS would be my choice for daily driving and weekend track use.
Based on my driving experience with the XS since November, I'll buy XS again. I do spirited daily driving with weekend highway fun drives.
What constitutes the best "road tire" is somewhat subjective. Personally, I want a road tire that can stand up to track heat and take the turns as well as/if not better than the more expensive RE-11 at much less cost. The XS is fine in the wet for DD plus a little more. I've driven the tires in temperatures in the low 40's. They start out hard at those temperatures but warm up after a few minutes on the road.
I don't know if I had anyone driving RE-11's behind me last winter but if there were any ahead of me they weren't there for long.
If I was looking for a performance tire for summer only I'd buy the XS. In my climate I get to drive extreme summer tires all year long and take another car with all seasons and chains into the mountains.