I've been using the XS series for quite some time now and it's generally become my favourite set of strings.
Soundwise and playability wise they're just brilliant - coupled with durability. I'm using a lot of open tunings and change quite frequently, the XS can take quite the beating and I'm facing a lot less string snaps than usual.
One word specific to the medium/light hybrids and why you want to get them.
I do use tunings where the bass strings are being tuned lower while the treble strings are tuned up. This set is great for those tunings, you don't get sloppy bass and your light trebles withstand easily being tuned up.