I bought this tuner for my ukulele, as I needed something small, light and easy to use, and I have to say that it does the job... most of the time.
The tuner is easy enough to use. It only has a couple of buttons to move around the modes, etc... For what I want it, it is just clip in, push the button, tune the hell out of those strings and keep on playing.
My big downside is that it is not as precise and accurate as other type of tuners. If being exactly in tune every time is one of your main concerns, you may want to look for a different gadget, specially if your instrument can be plugged in.
On the other hand, it gives a lot of bang for the buck. It is super light, discrete, easy to read even in the dark, power efficient, and it works with a good amount of instruments.
I like the finish of it too.
Update: I have just taken 3 stars away from the quality, as I accidentally dropped the tuner from a very low height (about 50cm) on a wooden floor and it stopped working completely.