I'm using this with my basses (G&L SB-2, G&L L-2000, Ibanez SR-300). It works great with the bass. It's huge funky fun and sounds great. Get it!
It's not perfect in two ways. First, there is no output volume or blend control. Makes sense in a cheaper pedal, but it can be felt if the rest of your chain is sensitive to dynamics. When you turn the autowah on, the resonant frequency can get a bit too loud...
Next, sometimes (for my more silent bases) I need to put the sensitivity to max. So the range is perhaps not tuned for bass. It's fine, but it might be interesting to have more range.
Overall, I love it. For the price it's a super-useful and fun pedal!