I'm not sure what kind of sound the original post was looking for, but the bigger issue seemed to me to be the ability to get a good sound out of a filter without tons of effort. I would have to agree with "Smurfy" that the 3 Leaf is not really an extreme, "wet" sound. However, the version 2 modification to the unit does add some resonance. I would say that the GR has a "natural" sound that can easily be dialed-in and be heard in the mix. We must also consider that this unit also works on guitar, as does the WMD Fatman and the Qtron+.
I have played on the EBS Bass IQ and found it very wet, especially with the toggle switch at the top. It's not an inexpensive unit, and I'd typically want more control of the sound relative to the price tag. For me, super-wet is fun on guitar but gets lost in the mix on bass, which is why I'm a big fan of the 3Leaf Groove Regulator.
So, if the person originally posting wants wet and easier to use than an EHX product, the EBS Bass IQ is probably a good choice, in my opinion. However, I wouldn't keep both the EBS Bass IQ and the QTron+ if I wanted variety in my filter line-up.
FYI, for a big, rubber bandy sound, I use an old, two-knob DOD FX25.
From what I was told, he's been working on yet another version that has more of the vintage Mutron III type sound. He actually changed out some range caps to accomplish this. Even he seemed real excited about how it sounds now. Ive been patiently waiting some sound samples from him.
BassIQ=YES