Feature:
Works by vibration from acoustic or electric guitars. No bleed when other players won't stop noodling when you are tuning. Auto-turns-off after a minute or so. Finds the pitch you are tuning pretty quickly and VERY rarely gets fooled by note harmonics (into thinking you are tuning A when you are tuning E, for example).

Quality:
I had mine for several years now-enough to replace the batteries twice and I don't play all that much these days. Seems to be well made. Gotta keep up with the DOME HOME case to keep the sticky pad clean.

Value:
Better than the Boss and Korg tuners I have used that cost about the same.

Sound:
Tunes as accurately as any I've ever used in 25 years - except of course, a strobe type tuner or big expensive rackmount.

Ease of Use:
Only downside is you have to clean the post-it stickum stuff that holds it onto your guitar every now and then with a little soapy water to keep it sticky. Not quite as quick to find the note on a Bass guitar.

Support:
No experience with them.

Feature:
It does what it does very well. Tunes quickly on everything from acoustics to solid body instruments.

Quality:
The only caveat is the adhesive backing. Keep it clean and it works great. Easy to clean.

Nothing out there, except maybe teh Sabine rack tuner, can top this one for ease of use and performance!

Support:
My tuner died and Sabine gave me a new one! In the time I had mine they put out a newer better version and they gave me the new one! No problems, no questions.

I have two of htese and am thinking of buying anothers.It's always there when you need it.

When you are preforming for $$$.

Got to be in tune; especially when you are preforming with a digital keyboard. Otherwise your guitar will sour up and your band and the audience too can heat this...!!!

So get a contact tuner that you can see even in the dark...