VXGI 2.0 performance if you’re using only VXGI Diffuse with settings for the performance, is really close to the performance you would get with an optimized VXGI 1.0.
Still it would need proper testing, but from my personal test you’re really around the same.
Now, if you’re using VXGI Diffuse and Specular together, performance are drastically better with VXGI 2.0.
Aside from Area light of course, a really nice addition is the ability to combine Diffuse and Ambient Occlusion, previously you either were using VXGI for it’s voxel-based ambient occlusion, or for its global illumination abilities, from now on you can combine both at barely any noticeable extra cost.
After several test run i still can’t decide if whether Diffuse+Ambient Occlusion is costing more than Diffuse alone or not, while the visual impact of extra AO is really noticeable and appreciated.