Hi,
Yes, I did, and I noticed that the Fab 3D viewer suffers from a large amount of textures and complex models where the Sketchfab 3D viewer doesn’t have this problem. From a logical perspective, Sketchfab has benefited from 10 years of testing by various artists, which has allowed them to perfect their platform. It will likely take at least 5 years for the Fab 3D Viewer to reach a similar level of quality.
Cheers
Barth