Yes, I have used Cleartones. I have used (and will continue to use) Elixir Nano PB Lights on my 615ce L30 for 3 years. I got wind of Cleartone (I think on the AGF), and after a fairly lengthy convo with the accessories guy at GC, I went ahead and popped for 1 set of the same specs of the Elixirs I use (PB, Lights). I needed a string change (which is why I had started the convo in GC anyway), so I swapped them out when I got home. I have been using them for over a month (maybe 2) and they are still on my 615.
HERE ARE my impressions:
- I don't like them as well as Elixirs... they don't sound ANY better, and I feel the Elixirs sound a bit better (slight if any)
- I don't like that, due to no coating, they are more prone to "squeal" or "scratch" as you move up & down the neck
- I don't like that they are even more expensive than the most expensive string I ever allowed myself to buy
- I don't like their color/aesthetic - I like the "bright-ish" gold color of the Elixirs vs the "dead-ish" copper color of the Cleartones
- I feel they sound virtually identical to the Elixir Nano PB when plugged in on stage (although so many things can effect THAT sound)
- I do not know yet if they last as long as the Elixirs I have come to know and love... we'll see
The main negatives that I personally have read about why people don't like Elixirs are COST, and COATING FRAY (neither of which bother me, since I have gotten used to the cost and they last long enough to justify the cost, and the fraying issue is just something I don't let bother me; a non-issue). Cleartones cost even more than Elixirs, and no they won't fray, but it remains to be seen (at least for me) if they will last (sound and look as good) as long as Elixirs.
Hope that helps.