Comparing base model to base model I think Cascade is quite a lot better than SDXL, but .....and it's an enormous but... It seems to have been shunned by the community.
Maybe nobody with resources to do training is interested in a model with commercial restrictions, or the multi-model flow was just too different for people. Not sure, but the output of the base model can be really nice. Not always, but I find the biggest errors are people taking on a painterly/waxy appearance rather than the arm turning into a leg body horror you can get with SDXL. I think the "compressed" Stage C works to keep the composition together across the whole image more.