I have not tried a lot of tuners, but I have been completely happy with my Sabine AX 2000 tuner. It sticks on your guitar (or other instrument) with a Post-It Note like sticky. It comes off and goes on with ease. Sabine suggests you not store it on your instrument since it could get really stuck. It also may be troublesome for vintage instruments that have some checking (might pull the finish off). You store it in a little plastic box to keep the sticky part from collecting dirt. It is easy to clean when necessary however.

It is chromatic with a 12 note even tempered scale. When you strike a string the appropriate note lights up. If it is red, it is sharp, if it is yellow it is flat, and of course if it is green, you are dead on.

If you aren't working at A440, you can strike a string and set it to work at that pitch. I find that useful if I capo high on the guitar and I know all of the strings are slightly out of pitch.

It runs on two lithium batteries and turns itself off (sometimes quicker that I can tune).

Because it basically uses a contact mike, you can tune in a crowd of other players. It is easy to lend to others or to switch from instrument to instrument.

I find it easy to use at gigs. It is about 1 1/4 inches wide and 2 1/2 inches long. Comes in black of fake wood grain.

The only drawback is it looks like your guitar has developed a goiter.

Being tune deaf, I love it.

Big RiB