AU or VST ?

[almapercus]

Is there a recommandation between these plugins format?

[Jerm]

I tend to use AU but it usually depends on the specific plug-in. VST is mildly faster but AU let's you specify automation ranges using real values, VST is limited to 0.0 to 1.0. Also with AU you can have sample accurate automation with most plug-ins. There are probably several other subtle differences.