A good little app, only one feature I would like, being able to pause a recording instead of having to stop and start a new one.
I owned Audio Hijack for years and since it's no longer supported and I can't use it with my Mountain Lion install, I was looking for something (didn't need Audio Hijack Pro (well, I could use it; but for me, the price isn't worth the extra features (most of which I don't need))) of equal audio quality and simple usability. I bought Piezo on a quick review and it's great, except for the lack of a "Pause" button.
Beyond that, I like it a lot and have had no issues with it's output quality, setup or use. For $10, you're getting a great product!