In 2008 I started playing Elixer Nanoweb Phosphor Bronze medium gauge strings on my acoustic guitars. I really like them. I wrote a post about them a few years ago (see post here). The downside to playing these strings is that they are expensive. A normal retail price for them is around $15.99 a set .
A few thoughts:
I play medium gauge acoustic strings. If I could go heavier I would, but my Martin has a medium gauge limit. I like the sustain they provide and that they do not bend as easily. To someone accustomed to playing light gauge strings a guitar strung with medium gauge strings might feel rough on the fingers. I’ve been playing medium gauge strings exclusively for fifteen years, so my fingers find light gauge strings disturbingly lacking in substance. I’d be more inclined to think about dying my hair blue than changing to light gauge acoustic strings.
I have already stated that I am a big fan of Elixer Nanoweb Phosphor Bronze medium gauge strings. I decided to try a set of D’Addario EXP Phosphor Bronze medium gauge strings on my Martin this month. From an economic standpoint they are a better deal than Elixers, running around $10.95 a set. For three days they sounded wonderful. But they did not hold up over time. It’s been two weeks and I’m considering taking them off because the bass strings are so lifeless. Not cool.
So I think Elixer Nanoweb Phosphor Bronze > D’Addario EXP Phosphor Bronze
As a side note, you might be wondering what the phosphor bronze contributes to the strings. You’ll find mixed reports on this. Here is what Elixer Strings says on their website:
They claim phosphor bronze contributes warmness to the tone. You’ll also find many people who swear phosphor bronze strings maintain their tone better over time. This was my conclusion years ago, but I have not tried Elixer Nanoweb 80/20 Bronze strings yet (they are a couple of dollars cheaper).
My loyalty to Elixer has been reinforced.
 Today I purchased six sets of Elixer Nanoweb Phosphor Bronze medium gauge strings from Strings and Beyond for $59.98. They have a buy three get one free promotion going on. If you spend more than $35 you get free shipping. Picking up my favorite strings for $10 a set is awesome!