Well, my Elixir Nanoweb PB mediums were far from wearing out, but I figure if I wait until they're dead, any new string will sound 'good' and it won't be an accurate comparison.
So, last night I pulled them off of my GSLJ (think 610) and put on the uncoated John Pearse medium PB's.
First impression, much warmer, less thump at the bottom, highs less sparkly. More balanced all around, not sure if that's a good thing yet. If the baby goes to sleep (or at least settles down enough to hang out in the bouncy saucer) I'm going to play some more tonight and see what I think.
-K