I had read mixed reviews abut this one but because Thomann are so cool about returns I thought I would take a gamble, and it paid off.
The tuner has both a microphone and a vibration sensor which means it can be used even in noisy situations , but I have so far not tried to change settings and left it on whatever is default.
I tuned one guitar with my software tuner and one with the Snark and then compared them. I know that my software tuner is extremely accurate and it seems that I can now say the same for the ST-2. It was almost spot on. It wasn't absolutely perfect but it was close enough that the human ear could not discern any difference.
I then tried it on a violin and found the same results, highly accurate tuning.
The display is bright enough to be seen in most scenarios from a dingy, smoke filled room to bright sunlight and even with a spotlight trained on it I could still make it out perfectly. This is very important to me as my eyesight isn't what it once was and end up playing in a variety of differently lit environments.
The unit itself seems reasonably sturdy and I wouldn't hesitate to chuck it my bag but I doubt it would stand up to being stood on or thrown at a solid wall.
Despite what I had read elsewhere it seems perfectly easy to understand and use and does come with adequate instructions, should you wish to check something.
The highlight for me was the metronome feature though. This can be set before use or started and then changed by tapping (just like a tap-tempo on a delay).I hadn't really thought that this would be any use but I found that having to look at the pulse, as opposed to hearing a tick, made me tighten up my playing and rely less on my eyes for changing positions whilst playing.
Although , obviously, this might well be a downside for many people. But this is after all an extra feature and not the unit's main purpose.
All in all I think this is really a pretty good little tuner and I am baffled as to why it gets such a bad rap. I definitely recommend it. There are better tuners out there and a whole lot of worse ones but if you're after an inexpensive but useful clip-on then this is definitely worth a look.