Simple test. Put Hydratone on any track. Boost at the frequencies of choice (let's leave aside boost/cut issues for the moment). Play with the "Fire" knob. Play with the Phase knob. Bring down the volume so you can engage it without a noticable increase in overall volume. Now bring in any other software eq you have, at any price, make the same boosts, adjust the level...and A/B them.
I think you'll be shocked at how flat even your most expensive software eq will sound in comparison. I was, for damn sure. It's that obvious. I've never had an eq that brought such a 3D sound to my tracks. The difference is night and day.
Drawbacks: Plenty of 'em. CPU hog. You have to install Pluggo runtime for it to work. The eq curve display is only roughly accurate, and more distracting than anything else. The action is anything but smooth.
But I'd go through a MUCH darker hell to get that SOUND. This is not a surgical eq, nor is it clean. It's all color, all mojo. You can choose any of four hardware eq models with each band, but the Fire and Phase controls really put it head and shoulders above any other colored eq. Being able to adjust the phase of each track while the mix is in full swing will bring amazing results. It continually surprises me how much easier it is now to get certain tracks to sit into the mix.
This is a great tool. If you think your tracks need an injection of life and vibe, you would be doing yourself a disservice not give this eq a serious look. Highly recommended.