Driver support with macOS is at best spotty and the supported models have several restrictions like not working for DRM content or iTunes, not having mirror/rotation support or needing that the Mac Pro GPU has METAL support - it's a very long list of restrictions. Some drivers even require instructions not supported by MP5,1 Westmere processors.
When you can get it working, it's slow, but useful for newer Macs that have native USB3.0, but it's not tolerable when used with USB2.0 connections.