Shunyata's Hydra 8 Version 2 vs V-Ray version 1

I'd love to know whether anyone has compared the new version of the Hydra 8 to the standard V-Ray. Would it be better (cheaper) and almost as effective to simply send in the Hydra 8 for the version II upgrade or by a used version 1 V-Ray, which are becoming more affordable every day.
I asked this question of Grant Samualson of Shunyata. If I recall correctly, Grant said it would be a close call, but he felt the Hydra 8 V2 would sound better.