I started using Elixir Nanoweb .012 gauge strings a couple of years ago and now use no other. (Sounds like an ad, doesn't it?). I have very acid hands and go through a conventional set like Martin Phosphor Bronze in a day. In other words, they lose their clear tone in a day.

To my mind, there is a problem with the 3rd and 4th strings, which tend to break more often than other makes. I took this up with Elixir Europe (based in Germany) who, though they didn't admit to a problem, sent me a couple of sets for free. Since then, I've started using a lighter, more flexible nylon pick for plectrum work, and the strings don't break.

I use them on my Martin, Larrivée and custom tenor guitars.