I've used D'Addario XL strings for many years now. I've tried other brands, but keep coming back to these. They suit me, and for me, they last a long time.
My only moan is that I've now had quite a few 0.010"s E strings unwrap at the ball end, which is something D'Addario need to look into remedying. But I've also had the same thing happen on Ernie Ball strings as well. It may simply be an occasional batch production problem, but when you buy a pack of 10 that have come from the same batch, and at least 50% of the E strings come undone, it is rather frustrating.
I've now taken to soldering the wraps on my high Es, which cures the problem, but it is a bit of a pain to keep doing each time.