In my opinion, Aquila make the best strings for your ukulele. The quality of the string itself is consistently high, they are nicely packaged, and they will make even a cheap uke sound good. I don't trust, and would not buy any uke that doesn't come equipped as standard with Aquila strings, I see it as a stamp of quality for the instrument and a vote of confidence by the maker.
I purchased these sets of strings as spares because I was going on a long holiday which involved leading some ukulele workshops for beginners. I give my ukes as lot of daily use, but I have never had an Aquila string break or fail in any way. However I thought that with heavy handed beginners thrashing away on ukes I should expect some string breakages, and therefore have some spares ready. Needless to say, the spare strings are still unopened in their packet, and all the ukuleles in use (equipped with Aquilas of course) suffered no string breakages, despite some terrible abuse by the students!
I nearly forgot to say, these strings not only have a lovely sound, but they are the best for staying in tune once they have settled in. And finally I should add that Thomann offer the huge range of Aquila strings at the best price you can find.