Feature:
Enough features for what it's supposed to do.

Quality:
Excellent quality.

Value:
TOTALLY WORTH A C-NOTE!!

Desirability:
Great product, and worth the money.

Sound:
Really quiet, and especially helps with boosting the signal.

Ease of Use:
Super easy. Adjust your input gain, turn up the volume until just on verge of feedback. Adjust first "null" knob until feedback gone. Turn up volume again, and do same for secondary annoying frequency. Use "null" knob number two for that. Voila!

Support:
Never had to use, but a friend says they're good.

Overall:
If you play an acoustic instrument (guitar, reso, upright bass, ett.) have to play at higher volume, and have feedback issues, this is an inexpensive and easy solution.

Feature:
It features exactly what they said it will. No EQ -- just gain/volume and two notch filters that WORK, plus a phase inverter switch that give you even more control over feedback.

Quality:
Seems very well made and road worthy.

Value:
What are you waiting for? If you have bad feedback issues, GET THIS! Totally worth $100.

Desirability:
Don't let excessive feedback ruin your gig. If you play an acoustic instrument (any), this will save your nerves. A must in the tool bag for any serious acoustic instrument player. I got it for Upright Bass (works great). I've also used it for acoustic guitar, resonator and ukulele. Works great on all of them.

Sound:
The sound is excellent. If you add more gain, you'll get more noise, but that's true of any pre-amp.

Ease of Use:
Easy - just plug in, turn up JUST UNTIL you start to hear feedback. Then, turn the first notch filter until it goes away. Then continue to turn up until second feedback frequency occurs. Do the same with second noth filter.

Support:
Don't know, but I hear they're easy to deal with.

Overall:
It works as advertised. I'm happy with it.