These strings are great when I put them on my Breedlove Atlas, sounds bright and different from the popular phosphorous bronze strings.It works great and sounds right; however, after I applied GHS fast-fret onto the strings, I feel there's something different about the strings, it becomes dull and kind of sticky feeling, not as bright and fresh as it used to be. After couple days, the strings are just dead. It lost it's bright color and the tone was just muddy with no high's and no definition on the low's, basically a corroded, dead strings' feeling.As a comparison, the fast-fret works great with my MXR and Elixir phosphorous bronze, so imo it's not likely to be the fast-fret's problem.It may be my fault to put string oil on it, but I'm not so sure if that's really the problem.Anyways, if by any chance I need to use them again(during emergence situation i guess), I would leave it w/out the string oil and come back for more reviews.