Very bright strings, similar to D'Addario Pro Steels, lots of midrange, modern sounding. Good for slapping, but when you switch to bridge pickup there is a nice growl. Would be intereting to see how 45-105 would sound - should have more meat.
Not a very objective view as I have been using them only for about 3 weeks, everyday palying with two live acts but so far they show no signs of loosing brightness/edge to the sound in contrast to D'Addario which usually die very quickly.
Although stainless-steel design they are less coarse than average. I generally prefer nickel for this very reason, but can live with this ones
So far they seem a good value for money, specificaly for Sandberg owners as their bases are specificaly set up for the very strings - action is exemplary