I'll preface this review by saying that I tried this tuner with an acoustic banjo. This tuner seems accurate when I cross referenced with it my other tuners at home. It found the notes fairly quickly and I was able to dial it in.
I've read some reviews that said they do not have any problems using this tuner on stage. I found my experience to be the opposite. Now, I did mention that I'm tuning a banjo, so that has some problems of its own when trying to tune onstage with other instruments playing. However, I do have some other clip on tuners (Crafter) which have no problem with interference from any other instruments (drums, bass, etc.) The reason I bought this one is because it was discreet and doesn't look like I have a robotic bird perched on my headstock.
I gave the tuner the benefit of the doubt and brought it out to two gigs, but I'm very glad I had my backup. The tuner would not find the notes at all. I tried it in different positions but still had no luck. If you are playing just at home or perhaps in a bluegrass/acoustic setting, this may work out for you, but if you are in a band with electric guitars, drums and bass, try something else.
Update: Above I mentioned that I used this tuner for my banjo..well, I gave it to our guitar player and while he was tuning up his acoustic in a quiet setting before our performance, he said, "Man, if someone even thinks too loud, it throws this tuner off!" The claim in the tuner's description that ambient noise does not interfere with the tuning is just plain false.