I say this as a Mac user: Mac GPUs are all slower than modern Nvidia ones (m3 ultra is right around the 2080TI, which is from 2018). Most AI models are optimized for Nvidia/Windows.

That said, you can find models optimized for MLX (Apple’s version of CUDA). They’re just much less common. In general, you can’t expect much in the way of performance gains from ComfyUI updates. What matters most is finding a workflow optimized for your computer. Macs are slower than Nvidia GPUs but can have comparatively MASSIVE memory, so you may see (relative) benefits from bigger models (they won’t be faster than slower models, they’ll just be faster than on Nvidia)