Overall it's a useful tool to tame your mix and keep it in check, especially when designing sound live or improvising.
That said, I found it not that easy to use in the context of setting it up during sound check. The VUE meter is a welcome feature that helps a bit in that regard but I felt I needed more experience with it to really be comfortable using it. When using it as an end-of-chain processor in a studio setting, it's definitely easier to control when you can take the time to do so.
Finally, it adds a certain noise floor that I could live without.
In summary, not bad, actually good but not awesome either.