I can attest that it works really well on my 6900xt. Compiling CUDA kernels is merely a matter of a using a #define shim. Also, provided you download the ROCm pytorch (and force compatibility with the HSA_OVERRIDE_GFX_VERSION) everything just works.
You can also run Stable Diffusion in cpu mode, if you don't mind it being slower. I have an NVIDIA card but it's not powerful enough to run it. I'm on Ubuntu.