Is it less predictive than point differential? I'm not saying I don't believe you but... ok, I am saying I don't believe you. (I am open to it, though). APoint differential is highly dependent on who you've already played while DVOA takes that into account.
That said, I don't think any metric or system is perfect and DVOA certainly isn't. But seeing how our team is doing in DVOA is just one more data point to consider in terms of evaluating our season and the current numbers (as well as the overall trend) are very positive.