Many reviews on this tuner and its brothers have mentioned slowness on acquiring the guitar low E. This video shows how minor (or even non-existent) the issue is if you put the tuner on the side of the headstock closest to the low E.
If you VIEW the video in FULL SCREEN, you can see the digital pointer, and how it moves as the two low E's on a 12-string guitar are tuned up to correct pitch.
Sorry about video quality (Amazon reduces their quality) and the cars in the background (I needed lots of light in the background, and I did not want to bring my guitar out into the snow).
The tuner also worked for a friend's acoustic/electric bass guitar. It took about a second to get the low E (on the bass guitar, remember), but it got it. He was able to tune his bass, and I my 12-string while a piano was playing (we were about 10 feet behind the soundboard of an upright acoustic piano that was also being amplified). Great tuner!!
When the Mode Selector Switch is set to "Chromatic", the tuner allows you to tune to any note, and the display will indicate the note, e.g., "D#". When the Mode Selector Switch is set to "Guitar" or "Violin", the tuner allows you to tune only to those notes that exist on a standard-tuned guitar or violin. E.g., when set to "Guitar", it allows you to tune only to the six standard guitar notes, and will display either "6E", "5A", "4D", "3G", "2B", or "1E". The Mode Selector Switch seems to have no affect on the tuner's performance. (This is a good thing because it works perfectly.)