Years ago I decided I wanted this pre, but through unforeseen circumstances I never got to buy it. Since then, I have upgraded my signal chain from a 1st gen Scarlett 2i2 to a Clarett. As I am starting a new production I thought: what the hell, just buy it. At this price you really can't go wrong.
And you can't. I have been using it for two day now and I must say: I'm very impressed. We use it for the vocal tracks on singer/songwriter music and the artist is so much more comfortable using this then going 'dry' into he Clarett (using the Rode NT1000 or the Audio Technica AT 2035). It eliminates background hum, airplanes and other stuff. The compressor tightens the vocals in a very musical way. I give his voice a very subtle boost in the lows, which brings his 'chest' sound up just a notch - brilliant.
Don't overdo it as driving this unit too high gives strange effects.
In conclusion: I always thought that the way to get a better sound is through better microphones and/or AD conversion. This is true, but the power of this nifty unit made me overthink this. So, if your vocals sound too thin or dull to your ears, you might stick to your present signal chain and invest in this DBX thingy instead of buying other mics.
4 instead of 5 stars for the hum the transformer in the unit produces. I have the same thing with my Kawai piano. I'll have to live with that. And the expander/gates filters it out anyway.