Prim strings have been the top choice for american old time fiddlers for decades, and this is how I've came to know them.
They are bright sounding strings with strong fundamental and little harmonics. For this reason, they might not be a good choice if your violin is bright to start with, or if you are a beginner and have trouble managing a loud and edgy fiddle. Also, if you are used to synthetic / nylon core strings (Dominants etc.), they are at the opposite end of the spectrum and might disorient you.
On the other hand, if your violin is kinda dull and muffled, or if you need a loud tone that punches through a jam, they are a great choice. Their zingy edge mellows out with time, and once they are settled, they become more balanced, with a sweet, ear pleasing presence. They are amazingly resistant to wear, body oils, temperature change and constant alternate tunings. If you like a fiddle that requires no fuss, no tuning or regular string changes, Prim will reward you. They are ROCK SOLID and, as far as I know, have no equivalents in longevity. My main fiddle has 10 years old Prim strings on it and they are still perfectly usable.
I think there's no such thing as a "5 star" string set, as it all depends on the violin, what you play etc. But in case of Prims, they totally deserve it, just for their unique ability to withstand wear and tear.
