Comment by vunderba

Yeah SD 1.5 is mostly trained on datasets of resolution of 512x512. That's why you'd get crazy multi-limb goro abominations if you pushed checkpoints too much higher than 768x768 without either using a Hires Fix or Img2Img.

There's not much of a reason to use SD 1.5 over SDXL if image quality is paramount.

A lot of people (myself included) use a pipeline that involves using Flux to get the basic action / image correct, then SDXL as a refiner and finally a decent NMKD-based upscaler.