I've gotta say, I tried the Nova Dynamics yesterday in my local guitar shop. Not overly impressed. Whilst it had a completely transparent sounds tone wise, I just couldn't get it to compress the way I wanted it to. Bear in mind that I have a certain sound in my head that I want to achieve, so the unit might work for you perfectly adequately.
I really had high hopes for the studio multiband model, but I have a feeling the crossover points of the multiband are voiced for guitar, not bass. So what would be the low band on guitar becomes low and mid range on bass. You also have one global attack control for this mode too, I would prefer to have slow attack at the low and fast in the high end.
I must admit, I like to go quite squishy with compression (think Billy Sheehan type squishyness), and this can really squash, but I just couldn't get the attack right on either model, it either sucked the attack right out, or had great attack and sucked and pumped the note fundemental.
Maybe you'll have better luck than me, as I was using the shops gear too in a quick lunchtime session. But if I can't get close to what I want quickly, then it's really not worth laying out that sort of money for me. The other thing that put me off is the 12v wall wart. I've recently got a 4 cable loom for my pedal board, which meand I can keep the power supply at the back with my amp, and it's not designed for more than 9v!
I'm gonna try out the EBS, multicomp at the weekend, I know it only goes up the 1:5 ratio but I may have better luck with it being voiced for bass.
On the original subject, the Nova system does look rather handy, I'd be intrigued to try this out on bass too, and see if the compression model work better, would be great too if the od/dist models can be blended with clean tone. On the plus side, they have one in my local shop and it is quite small and incredibly light.