Great Utility plugin. Especially for the advanced Pan settings (Pan Law, Panning and gain control individually for each stereo channel), which are not found in DAWs regularly, a precious little gift.
The Dual-channel Volume control up to -Infinity is also pleasant and useful. Plus you have an "Input" control to readjust the gain independently if necessary.
Offers a vast of special features (my favorite - "Silence when playback is off" option if you want to stop annoying delays/reverbs), but I think the 6 knobs and 2 sliders at the top left corner usually are the ones you use frequently.
Only bad thing is that Resizing the GUI and loading a costumized interface is only available if you pay them the 49$ for the FreeFxBundle upgrade.
Another thing: I'd wish to have a toggle for the lower left parameter section (like for the meters and toolbar), to have a clear focus on the main features of the "Basic" section.