I find that different types of string perform better or worse depending on the string tension. What it says on the package is not always best, at least not to my ear.
Recently, for instance, I installed Aquila Lava's(tenor low G, #115U) on a 16.5" scale length tenor. The performance of the strings was extremely disappointing, and after several days I concluded they were rubbish. After that, I tuned the uke down to Bb as I frequently do. What a world of difference it made. I actually quite like the Lavas in Bb. To me, on that ukulele, they sound dead in C but with a bit less tension they sound just fine.
The experience was a reminder not to forget to experiment and find the ideal tension when trying out a new set of strings on an instrument.
To address your question:
Scale length and tuning combine to determine string tension, so I believe that those factors should be your primary considerations.
There is an 18" scale length tenor in my collection that I string with either Oasis or Worth. It is usually tuned to Bb because I like how the lower pitch compliments the rich overtones of that particular instrument with those particular strings. Both of those brands produce fantastic results, to my ear, on that ukulele in that tuning. I would not hesitate to recommend either brand.
I will go farther than Jim did and say that you must be open to experimentation and tuning in different keys if you want to get the most satisfying sound out of your ukulele with the strings available. On top of differing results due to string tension, there is an additional factor of personal taste that will color all conclusions made on the subject. You can choose to take it easy, pick a string set, and hope for the best; or you can buy a half a dozen different string sets and spend the next six months experimenting with strings and tunings to find out more about what you, personally, will like best.
The latter route has been rewarding, despite the confusion and consternation along the way.
