The Polytune 3 is small and very useful. I keep it at strobe setting and always on. The Ploy-mode is nice, but not always 100% in line with strobe, so I tend to tune string by string anyway. I have not gigged with it though.
I use the Buffered Bypass and no issues there.
Only issue I have is when I accidentally hit the stomp and mute it, and I look for faults in the chain until I remember. But I can't blame the pedal for that.
Pros
Small footprint
Very accurate and sensitive strobe mode
Good buffer early in the chain
Cons
Not really, but would have liked the poly and strobe to match better.
Built in splitter would have been useful
I can really recommend this tuner.