The interface is pretty straightforward but you have to pay attention to the controls, there are a lot of (non-intuitive) things going on. This is for someone who wants to listen their way through cleanly touching up a sound. It’s subtle. (Or musical. People always use that term—it just means you can’t do anything really drastic to the sound.)
Check out the “passive” harmonics and the slight gain in the high frequencies. Notice though the MST (mastering) version has an almost flat response.
MST / Mastering version: