Manley Massive Passive

After years of curiosity I bought a Manley Massive Passive and placed it between my Classe Preamp and Classe monoblock amplifiers. I know there are many audiophiles out there that are dead against any tone control, including myself, until this Manley MP arrived today... amazing! I don’t know why Manley doesn’t market this unit to consumers. Best 5K that I’ve ever spent for my audio system. Even set in bypass mode, it makes everything sound amazing. Has anyone else had the pleasure of buying one of these?
I heard a set of Design Acoustics speakers dialed in using a Soundcraftsmen 10-octave band equalizer calibrated to the room using a SPL meter. It was the epitome of tonal neutrality. This was back in the mid-1970’s. 
Just bought a used one, coming next Monday, will let you know.
so you recommend it to your audio system?