If any of your workflows rely on cuda (or any form of gfx compute), you may have a difficult time achieving comparable performance. hopefully rocm is directly packaged for arch + derivs soon, like it is with Fedora, as you'll be able to use that codepath for OpenCL if they don't directly offer support for HIP or ROCm.
My typical hangups there would be like, digital film production and other forms of rendering, CAD, physics simulations, and client apps like Folding@home.