Just tested Mistral 4 too in Vibe and it's slow. It works well, but is way too slow. Switched back to Mistral's GLM5.3, which is awesome.
Edit : working with GLM5.3 now, it's also slow. Maybe Mistral's under heavy load.
Disclaimer : Not Cofounder of The Forecasting Company here
How are you accessing Mistral 4 from Vibe? The only ones available on my end are Medium 3.5 and GLM-5.3 despite having a Pro subscription.
I've been using Mistral Large 4 and some of my other friends have as well.
Something is going on with the performance (as in speed of the service, not quality). Some days it's quite fast, some days it's so slow I interrupt it because I thought it was hanging.
I think they're shifting hosting capacity around, or otherwise messing with the model. Note that it's still a "preview" version, meaning they're still training it further for the final release and they are likely still figuring out the optimal hosting configuration as well.
It wouldn't surprise me to see further changes in both quality of the model and speed before the final release.