I play on Macbook Pro (4GB VRAM; 16 GB RAM), dual boot, and I just wanted to note that the mac version of the game is *infinitely* slower on Mac OS than it is on Windows on the same machine. Using Vulkan on Windows, the game runs much much smoother (tested on High and custom settings on both boots) compared to the OS X version. It's not a deal-breaker for me, but it's a pity that the game doesn't seem optimized for OS X.
One of the biggest problems, with the OS X side, is that the saves take absolute ages to load, and there's still, even after all the new patches, something leaky about them -- the more one reloads, the longer it takes, until each save takes a good five minutes to load. So my guess is that the Mac version is still leaky, memory wise. I don't have the same issue on Windows.
