The weight range is inbetween 0.8 to 1.6, the sweet spot might differ depending on which version is being used and what prompt is being applied as krea 2 heavily relies on prompt, so if there is any aesthetic description or characteristic description, it will affect the prompt.

Recommended settings for Krea2Turbo:

Sampler: er_sde | euler,

tbh your choice, same for scheduler. Whatever gets you the aesthetic you want.