I've put these on a Harley Benton Custom Line Manhattan-Standard and used it for recording; they have a rich and powerful sound which enhances the acoustic resonance qualities of this particular guitar. The advertised long tone durability is not just a marketing hoax, and it's something for which I've known Blue Steel strings for a long time. The tone quality does not deteriorate after the first few weeks (like it is the case with certain strings), and the strings don't have a particularly sparkly and bright tone to begin with; it's reasonably balanced throughout their entire lifetime.
I've used their acoustic counterparts on several acoustic guitars and used to break them relatively often, mostly due to my heavy strumming on acoustic guitars trying to keep up in a 15-piece acoustic ensemble. These don't see that much abuse, but nevertheless they seem very durable with no breakage and no rust after three months of fairly regular use (casual half-hour playing every other day on average).
I would recommend these strings as poor man's Elixirs for almost half the price. Based on my past experience, they outperform D'addarios and Ernie Balls in the same price range (in regard to durability and longevity).
