While I certainly hope 7128 does well and they are one of the most advanced Polymerase (though not by as much as I once thought) I did a very back-of-the-hand calc and to me the ITMN is a better value prop but I am biased
If I were to invest in VRUS (and I am not contemplating it) I would be looking more at what comes next vs. what other Polymerases are in development. I get the sense Roche is likely going to add a 3rd (perhaps in addition to Ribavirin) compound to the all oral mix in the mid-future. Could be a non-nucleoside or helicase inhibitor. Wouldn't even be surprised to see another protease (though people don't seem to think 2 portease inhibitors give you as much in the longer term) or even another mechanism I never heard of. The next generations for VRUS seem to be follow-ons that are more potent and better pK but I don't think they are working on anything that would compliment 7128.