Haven't tried it myself, as the OB1 is all I need for dirt/bi-amp, but what kind of music are you playing? I would assume that both are high gain, while the Thunderverb is a bit more trebly whereas the OR has a bit more ORganic sound (har!).
When I'm not busy playing a bassist on TV, I play guitar and love Orange gear, but I find the Thunderverb a bit too nasally for my tastes (stoner metal), so I prefer OR or even Rockerverbs. Of course, those come with a lot more lower end, which might muddy up the signal when blended with a traditional bass amp. Which amp model do you prefer in Amplitube?
I play this here, I don't know what to call it:
