Firium - the Adobe Photoshop of plugin eq's. What we have here is a linear phase equalizer with the ability to draw the eq curve and process the left and right channel separately, or even oppositional. So you can be sure that your mixes won't suffer from ugly sounding phase distortion. It delivers a sound colour that is very hard to beat, for you won't find it. The processed audio file still sounds so natural and only very extreme settings could change this.
A very helpful and simply unique feature to the Firium is the ability to match the sound of two audio files. First you load the source file (the one with the desired sound) and let Firium analyze its eq curve, then you load the target sound file (which should be manipulated) and let Firium do the same. Once Firium knows the eq curves of both audio files it can slip the source characteristic over the target file. This feature can be very helpful during the master process, when you want to have a consistent sound.
the Firium sounds invisibly awesome and is easy to set up. The documentation is good and extensive, and you won't find a better mastering eq with this sound and functionality (at least this will be a hard task). The little helper has grown up.