I've got one, it's worth $20 to me because it has a wet/dry blend. It's not worth a lot more to me because it's hard to get that knob in the exact spot I want. However, once I get it in that spot I love the tone. I'm going for a Chris Squier distorto/fuzz with clean bottom. I've gigged it several times now, it's solid but works best using an ac adapter.
Now everything is clear -- in mind and in tone. I have dewired all of my amps. They now run off of broadcast power from the mothership. ALL YOUR BASS ARE BELONG TO US!!!