Feature:
Just sustains - the neck pickup is gone, and no harmonics.

Quality:
Too bulky, switches are hard mounted, so if you're cramped for space, you have to de-solder them and add leads, which is a royal pain. Board has some strange circuit material - not copper like regular boards, so if you damage it, good luck fixing it. I'd say this was made for Fernandes to put in its guitars, and not for people as an aftermarket product that is now selling as. The Sustainiac board is MUCH smaller and easier to mount in many cases, unless you want to rout a special compartment for this thing.

Value:
Due to the bulkiness, fit and finish of the parts (board looks like most of it came out of a transistor radio when for the money it should be ALL SMDs and much smaller - yes, I know my electronics), I can't give it a high rating. 5 is neutral for me, but I'd rather have a Susutainiac, quite frankly.

Desirability:
I use it a lot - it fits my playing style very well, but it devours batteries like no one's business.

Sound:
Infinite sustain? You bet - while it eats the battery. But it does sound good.

Ease of Use:
Just flip the switch and play your unending notes. If you've performed on stage, it's like having your amp cranked to good sustain levels, but without the usual necessary blistering volume.

Support:
Don't know - never contacted them, but I'd be surprised if they'd honor the mods I had to make in order to make it fit into the control cavity of the guitar it's now in because I was NOT going to rout a cavity and ad another plate to the back of this beautiful guitar - I didn't use their battery box either for the same reason.

Overall:
Already bought a Sustainiac as a better choice - even for the increased price. I'd describe it as a "budget Sustainiac" for a non-budget price. Not all of us are rich pros with the bucks to buy anything, and this thing costs more than a hand-made-in-the-US Fralin pickup, but isn't - it's most likely made in China for a pittance.