I haven't tried Micro Bass II. EBS is a good friend of us low end guys / girls; it wouldn't be bad at all in anyways. On the other hand I think we should evaluate ValveDrive in some other category because Sansamp, Microbass, Radial BassBone, etc. are all DI available pre-amp boxes. Like I'd compare BlowTorch and ValveDrive or alike...
If the case is the overdrive sound, I'd still say hands down ValveDrive for my personal taste

. I like that tube driven grit blended with the growl of my P bass.
The next step from here would be an all tubes head in means of sonic upgrade for me
