I'm usually cautious when a company claims to have found the magic sauce to make anything taste better. In the past months, I've tried and used a whole lot of tube/tape emulating plug-ins and improved my understanding of saturation a lot. However, so far, I found that it mostly helps make good sorces sound more interesting or shape them into something else. Bad sounding sources continue to sound bad.
And along comes this nice plug-in. So far, for everything I sent through it, it has indeed been an improvement. I would describe the effect as cleaning up the high mids and extending the audible information into the treble end. Interestingly, this also balances the perception of lower mid and bass.
What that means is it will remove annoying characteristics first and then allow you to enhance the remaining signal without sounding artificially excited/enhanced (if you resist the temptation of over doing it). When you bypass it, the original signal will sound unpleasantly resonant in the upper mids and more restricted towards the treble end, as though treated with several low-pass filters with resonance turned up.
So far, I tried it on self-recorded acoustic (one Røde NT5) and electric guitar (classic Strat through Lehle Sunday Driver into FireFace Hi-Z), on vocals, on Logic's drum kits and on a church choir recorded by my dad with a Stereo mic. In all cases, the results were an improvement. Easier to mix in case of the single instruments because there seems to be more space available after treatment with the bx and more up front and more pleasant in case of the stereo recording. So basically, what you'd expect from gentle saturation, with the added benefit of being able to gradually tune out nasty frequencies.
i do wish there was a frequency knob in addition to the intensity knob, but even at its current state, it's a very helpful tool which makes any further processing and the mixing process much easier.