This was actually even smaller than I expected it to be. It lives quietly and comfortably on the head of my 5 string Ibanez bass. I can tune my bass perfectly with it, however it takes a little more time and work than something like a standard Snark. Even the Snark has a problem with the low B string, and this tuner struggles a little harder to hear it. It also has a little more trouble with the low E than the Snark. The other 3 strings pick up nicely, but there is still a delay between when the string is plucked and when it displays anything. A quick harmonic check (by ear) on all strings is helpful to fine tune.
While on and not receiving input, it seems to blink continuously, I guess to let you know that it is on and waiting to "hear" a note. This is confusing and makes it look as though it is malfunctioning at first, although it does not appear to be. The metronome function works nicely (but silently), but I'll probably never use it. The ratcheting arm holds onto the head nicely, and does not slip at all. I think I prefer it to the padded spring clip on a Snark. The tuner swivels on the clip, making it pretty easy to see from most angles. It would be nice if it was more like a ball joint than a swivel for even more angles, but I think that would increase the size. It is helpful that the screen can be flipped to accommodate my preferred orientation. It is set to A440, but that is very easily adjustable if desired. The controls, in fact, are very simple and easy to use.
Overall for about 12 bucks, I'm happy with it. That is, as long as it continues to work properly, and the additional time required to use it doesn't get annoying. I have not yet tested it on other instruments, but from how it works with my bass, I think it will actually work better on something like a guitar or mandolin.