While you're waiting for some real benchmarks, this may help...
"The performance should be therefore a bit slower than the Radeon RX 460, which is similar to the GTX 965M. It is the only card in the MacBook Pro 15 line-up that features more than 2 GB VRAM (Radeon Pro 450 and 455)."
notebookcheck.net
So expect performance to be somewhere between a 960m and 965m.