The configuration of the D.W. Fearn VT-7 isn't too complicated to figure out after using it for a short while. Each of the two channels are identical, each consisting of ubiquitous compression parameters for threshold, gain, attack, release, and a harder/softer knob. Each also has a VU meter which will view either gain reduction. The unit has a switch which allows you to either link the channels or use them separately. I've never seen a manual for this, but if you've got any experience with compressors you won't need one.
Upon immediate usage of the D.W. Fearn VT-7 I was blown away by it's superior tone quality. The vacuum tubes inside of this make the VT-7 a thick sounding, unstoppable force. It is easy to use so I never have any trouble getting the exact sound that I want out of it, which is a big plus as it can certainly be a struggle to do this with other units. I would say that even though I've had the chance to use it on vocals and snare drum, that it can be used for any application you'd like, as it just sounds that good. Of course some things will sound better than others, but as long as you have something in mind I think you'll be able to adapt the VT-7 to whatever you're thinking.
Without actually hearing the D.W. Fearn VT-7, it is hard to take my word for it. If you're truly interested in the VT-7 or something like it, I'd highly encourage you to get out there and get your hands on one to try. The price is of course expensive, as will be the case with any high end compressor that you are looking to get. I can't say that this is necessarily better than the other classic and high end compressors out there, but it is certainly on the same level with most of them...