When it comes to strings I am very cautious about the reviews in general as often it is a matter of taste, feeling and last but not least "habit".
My regular sets have been the D'Addario Nickel Bronze 12-52 BT or 12-53, which are in the Euro 11-12 range, while the XS is in the Euro 19 range.
Note, that I am not a fan of coated strings, but in this case I decided the try just one single set for fun sake and make sure my regular Nickel Bronze sets are still the best choice for me.
Having tries the XS strings, I must admit that I am NOT disappointed by this set, but pleasantly surprised and I am sure they will become strings I will most likely often consider in the future.
In short:
A very nice set of strings, they feel very good, tuning immediately very stable and they do sound very nice.
Try them at least once :-)