I've used them in the past. They sound solid (kinda middle-of-the-road tone-wise) but they seem to lose their 'zing' much faster than some higher quality strings.
I like their relatively low tension and if you're not worried about treble & snap after a few weeks of solid playing, they're a good value.
I've switched to ClearTone strings when I need roundwounds, which feel/sound very similar to the MF strings, but last forever with their coating.
