t is interesting though that Gaillard spends so much time on the subject of VRS - which everyone here knows is my favorite weakness of the design.
It's not a weakness of the design though. The V-22 is LESS susceptible to VRS than normal rotorcraft. The rate of descent limitations given for the V-22 mirror those given for almost every other helo--no more than 800fpm at less than 40 knots. Those are the same limits that I was told in the TH-57(B206) and the same as the CH-46E. They are precautionary, and based more upon the limitations of pitot-static airspeed instruments than anything else. Stay above those, and you'll definitely stay out of VRS.
To enter VRS in the V-22, you have to be descending at more than 2000 fpm and nearly vertical. That's crazy fast, and easily avoided. Should you somehow blow through that, the V-22 has an out that no other rotorcraft does--tilting the nacelles.
Granted, the consequences of VRS are worse in a V-22 than a helo, but seeing as it's harder to enter VRS and easier to get out of it, I think that concern is largely mitigated.
I think the cost and reliability criticisms of the V-22 are valid, though both are improving over time. As far as performance, though, nothing else holds a candle to it.