That's what I've heard too biLL (number6). I've been using the nanowebs (standard and PB) on both my guitar and bouzouki for a few years now and expect to get breakages due to retuning in various ways. My guitar has a long scale and I use medium gauge so the tension is pretty high, though recently I have been tuning down a tone for CGCGCD/DGCFAD) (DADADE would be asking for trouble) and using a capo. Whenever I have an important gig to play, I always put on a new set and have never been let down, however during the lean patches, I've left strings on for a few months and still been happy with the tone. They are expensive but I think they are worth it.