Really appreciate that Meta published both results+model quants and didn't just make some bs claim about a new sota quant like most other bigger companies would've done.
That said, as others have pointed out, and as it's also written on the blog post, they are entirely different methods. QLoRA requires access to the full training data, while theoretically you can apply SpinQuant to any given model. For example, they also apply it to Mistral, not only to their LLaMA.
(QLoRA also takes some time and compute to apply, but since SpinQuant also implies learning some weights, I don't know if it's actually faster/cheaper, too)
Definitely nice to see them not cherrypick results - makes them more believable that its not the best along all axes.