Have you seen all the issues in the Unity forum? At least 3-4 months to squash them. Another 1-2 for future issues. A month for an optimization pass. Maybe a month for a future feature rewrite (like the network one).
Those are my estimates, and I often find my estimates too optimistic. I'd love to be proven wrong, though!
I really like Smiteworks. Great guys. But, prob cuz of such a small team, they are slow developers.