I've been using my polytune 1 since shortly after its introduction. No problems as of yet. Shortly after the mini's introduction I purchased one of those for my nano board. No problems there except for an introduced hiss at the front of the board, so I put it last in the chain and it has been fine. I probably should have returned it for the hiss, but never got around to it and it works fine at the end of the chain.
Z-Plus Maz-Jr 2x10 (sacrificed for Z-Plus) Therapy Antidote (great amp traded for Therapy to save my hearing; sorely missed) Rte. 66 (gone, but not forgotten) Carmen Ghia
"Well it's too late, tonight, to bring the past out into the light" (u2)
"well the last man standing get's to walk on the graves" (m.stanley)
"I have stopped instead of started,
and i have watched my children grow,
stood by graves of friends departed,
and found out just how much I do not know" (m.stanley)
PT-3 in use 1yr now. Running in always-on buffer mode. Only complaint, footswitch remains functional in this mode, and if activated the signal chain is interrupted. One nice feature when 9VDC is removed the PT-3 defaults to bypass mode.
I have a friend who had a Polytune go dead after about a year of use. I don't know what model it was. I was considering getting one until I learned that. I'll stick with my TU-3. Boss stuff is virtually indestructible. Actually the tuner on my board for the last few years has been the one in my Line-6 M5 multi-effect. It works great and I get the benefit of having all those vintage effect models, all in a fairly small footprint. $150 new.