Great for most guitars. It won't be a 100% secure fit on all headstocks but no clip on tuner is. Good grip, sits nicely in place on MOST headstocks, easy to handle. Not a lot of features but in my opinion that's a good thing for this type of product. The less clutter the better.
Triggering and tuning accuracy is very good for a clip on. Not as precise as a strobe tuner of course but for tuning on stage or at rehearsals that's just a positive. Trying to tune a guitar perfectly on stage with an ultra precise strobe tuner can be a frustrating experience for both musicians and the audience!
I wouldn't use this tuner for adjusting intonation. It's not precise enough for that. But it's great whenever you need fast, convenient tuning and it's precise enough for most situations.
Not quite as good for basses though. It struggles a bit with the E-string on some basses and is borderline useless for a 5-string. Still, no worse than any other clip on tuners I've tried.
The display is pretty good. In most situations the monochrome setting will work fine but on dimly lit stages you may have to use the full color display, which will drain the battery a bit faster. It will still last a reasonably long time though.
The build quality is very good for the price. I've dropped it on hard floors on many occasions and it's still working perfectly.
A real working man's tuner. If may not be the most precise but it's precise ENOUGH for most situations, works flawlessly for most guitars and can handle life on the road.