Using an LSTM model for finance predictions I found these benchmark results:
TF 2.7 GPU - 188 Seconds (tensorflow-metal 0.1.2)
TF 2.5 GPU - 149 Seconds (tensorflow-metal 0.1.2)
The slowness is expected due to a small batch size.
TF 2.5 CPU - 6.91 Seconds
TF 2.5 CPU - 4.66 Seconds (added disable_eager_execution())
TF 2.7 CPU - 4.47 Seconds
So TF 2.7 (master) is about 4% faster using CPU. The metal Plugin is way slower with TF 2.7, but at least it works to enable the GPU.
Apple should make the sources for tensorflow-metal available on git and ensure to update it regulary for each TF main releases like currently 2.6.