Fantastic, but be careful of the lower action
I have to say, I have really been impressed with all of the Rotosound strings I've tried. I think the Jumbo Kings are a very underrated string and these seem to be pretty much the same strings except for the "contact core" that lets the core wire sit on the bridge. I put a set of 12's on my Seagull and the tone is just beautiful! Full, bright, and lots of bottom end on the E and A strings. Great sustain also. The only issue I have is that the lower action on the 4 wrapped strings is pretty dramatic and the difference it causes between them and the two high strings is rather awkward. Also, there are a few notes that get fret buzz because of the lower action. If I decided to play with these exclusively, I would adjust the truss rod and file down the string notches on the nut for the high E and B strings. But..... I think I'll have to wait and find a guitar I'm willing to do that to. In the mean time, I'll just say they're great strings, but I probably won't get them again.
Full, bottom end on the lower strings.
ConsThe lower action causes some problems.