I use these singles to replace the 6th of a std set on my Floyd Rose equipped guitars.
I play exclusively in Drop D, and replacing the 42 with a 50 provides perfect tension, compensating for the detuning.
I bought these strings to check them out and to compare them against the ones I currently use from another brand, because the price is considerably better (cheaper) since they can be purchased in a pack of 6 instead of individually.
After a few months, I can say that they're quite good. They're bright, clear and endure heavy use and abuse without breaking or any other issues.
To be completely honest, I think that the other brand I use is still a tiny-winy bit better sounding and durability wise, but if like me, you tend to change strings often, the price difference tilts the balance this way.
I'm happy with these, and completely recommend them.