We've used Snark tuners for a long time: 2 headstock and a pedal tuner. All have worked flawlessly over the years. They are fast and accurate. When it came time to get more tuners, I didn't hesitate to go back to Snark. Great value.
The ST-8 may well be the most accurate, easy to use and easy to see chromatic tuner available for under $20.00. Great for on stage or anytime.
This is my first headstock tuner. I have a floor tuner that I use with my gig setup every Friday and Saturday night. However, given the noise in bar, if that tuner ever failed me, it would be difficult if not impossible to switch to and from the various tunings I use while performing. I really like the size and color readout and it is very accurate and handles any tuning you might want to throw at it. I'm very pleased with it and highly recommend it.
Second snark I've bought from shoreline, fast friendly service and delivery to New Zealand with a bit of humour thrown in :)
I have several of these for all of my instruments. I use it on electric and acoustic guitar and mandolin. Very sensitive and fast tuning. One thing I found though is that it is a little hard to see in outdoor situations even in indirect sunlight, but for the price you can't beat it!