Fearn and Massive Passive are different animals. The Fearn VT-4 (I'm assuming, to which you're reffering) is a Pultec style EQ with a mid cut and few bonus frequencies. The MP is a two channel, four band equalizer, with additional high pass and low pass filters.
I used to own a MP (years ago) and it's fantastic. It really accels in the mid sculpting department. The Fearn VT-4 is the best you can do as far as the Pultec thing. Do a seach, there's lot of posts on it. People across the board rave about them. I haven't heard it, so I cannot comment.
As far as the Viper's EQ??
You must be confusing it with something else.
