I bought this string, along with a PL030, PL020 and a PL013, to change the tuning on a Tenor guitar to "Irish tuning", E, A, D, G.
I wanted sufficient tension to get a good tone, but not so much that I needed to adjust the truss rod. I've always used Phosphor Bronze on my acoustic guitars, and wanted a similar tone on the Tenor guitar.
The strings work well, the phosphor Bronze of the 42 and 30 have that nice tone, while the plain 20 and 13 complement the others well.
If you're considering trying different gauges of strings on your guitar, be it tenor or 6 or 12 string, Daddario have a good range of different diameter strings, so you should be able to get exactly the tension you require.