With VMware talking about providing Metal API support to enhance their 3D performance, I decided to run a 3DMark benchmark test to compare performance. The good news is that Parallels still outperforms Fusion by a fair margin on the 3D graphics side. However I did note that Fusion has caught up considerably from the previous versions when I ran the test, and they do have the edge on the Physics test--so there's still room to improve for Parallels.
Cloud Gate Test
Parallels:
Overal Score - 9728
Graphics Score - 31131
Graphics Test 1 - 139.51 FPS
Graphics Test 2 - 131.44 FPS
Physics Score - 2856
Physics Test - 9.07 FPS
Fusion:
Overal Score - 9530
Graphics Score - 12730
Graphics Test 1 - 53.90 FPS
Graphics Test 2 - 56.88 FPS
Physics Score - 5070
Physics Test - 16.10 FPS
Cloud Gate Test
Parallels:
Overal Score - 9728
Graphics Score - 31131
Graphics Test 1 - 139.51 FPS
Graphics Test 2 - 131.44 FPS
Physics Score - 2856
Physics Test - 9.07 FPS
Fusion:
Overal Score - 9530
Graphics Score - 12730
Graphics Test 1 - 53.90 FPS
Graphics Test 2 - 56.88 FPS
Physics Score - 5070
Physics Test - 16.10 FPS