Practically anybody actually creating with this class of models (diffusion based mostly) is using ComfyUI. Community takes care of quantization, repackaging into gguf (most popular) and even speed optimizing (lighting loras, layers skip). It's quite extensive
I personally find nothing about ComfyUI to live up to that name. Node-based workflows are unruly, and you have to know in advance what you need to do for anything to work. Just poking around and figuring stuff out is nearly impossible even for technically literate but AI-inexperienced folks.
You could argue that is what pre-made workflows are for, but that doesn't work super well for users that are off the blessed path in terms of not having Nvidia hardware like everyone assumes. I personally find using stable-diffusion.cpp on the command line to be considerably easier to figure out. Last I saw, it's even shipping a usable demo web ui for those that really want one (my workflow benefits from heavier scripting, so point and click is far too slow and clunky).