I have used Rotosound steel strings on and off for years and you consistently receive a product with the same pro's and con's.
Pros:
-Bright 'zingy' sound
-Deep, solid low end
-Rough feel (might not be for everyone but I prefer it)
-Nice covered string ends (stops the machine heads from getting scratched)
Cons:
-The tone 'dies' rather quickly, especially if you sweat on stage
-When the tone 'dies' you are left with a clunky, unpleasant tone
-For me the A string seems too light gauge and the D too heavy
To summarise, I absolutely love the bright tone of these strings, but that tone just doesn't last long enough, leading me to look to other brands. Other brands may not be as bright as Rotosounds, but the tone they give you seems to last a lot longer, and can still be pleasing when 'dead'.