What the DCR1200 basically does is degrades the sound quality, introduces hiss and adds a dull element to the sound. Nothing you'd want, as far as I can see.
It cuts frequencies by ~ 60dB, and boosts only 4dB. It's made for live DJ use, hence the little boost.
Links for you:
Right, the PQ-4 has been replaced by the PQ-3B, I'm just a couple years behind hahahaha...