Okay, I'm getting a FSK-101 sustainer kit for my guitar. I was wondering a few things:

Can you wire it to the master volume knob when using it as a neck pickup?
Same with master tone?

Or does it come with it's own volume and tone knobs?

And, is it considered an active or a passive pickup?
My best advice is get a Sustainiac instead of a Fernandez.

This site should have most of your answers: http://www.sustainiac.com/st-pro.htm

Otherwise, call them at 317-340-1161 and they'll be happy to answer anything else. They're not a huge company, so it's not cool to waste their time with questions that are already answered on the website, but they are great folks and very helpful.

With the Sustainiac, yes you can wire it to master volume and volume tone.

I would think you could do seperate volumes and tones, but mine's not set up that way, so I couldn't tell you for sure, but you can figure that out from the website--you might have to download the manual.

I'm thinking that volume and tone knobs are optional with these since lots of people like using them as push/pull knobs to activate some of the different features.

These are active; they convert your passive bridge pup to active and IIRC, the neck pup isn't actually a pup, but rather a driver. The neck sound comes from the bridge signal processed to emulate neck tones. It does a good enough job that some of the most discerning professional musicians use it.

My take on it is that the Fernandez is a cheaply done knock-off of the Sustainiac, but that it can cost more, depending on where you get it. There is no middle-man with the Sustainiac--you get it directly from them. They'll even install it for you if you want.

I strongly recommend routing the guitar for a decent battery compartment (Sustainiac can supply that too). It's not a big deal to do (or get done if you don't have a router and the right bits), but it's so much more reliable than the alternative options.