Sorry, I never got much into Scala 2.10, I'm on 2.9.2 and this impression I got from Odersky's pieces of opinion about it, as from what I remember the initial p

Sorry, I never got much into Scala 2.10, I'm on 2.9.2 and this impression I got from Odersky's pieces of opinion about it, as from what I remember the initial proposal was for disabling those features, instead of plain warnings, but I guess that changed and it's my fault for not double-checking before giving it as argument (as a disclaimer I'm not an authority on the matter, I'm a rookie too). I've explained in another comment below what I meant when using the word "experimental". Indeed I don't remember M Odersky ever using this word, but he did use "cutting edge" when giving the rationale for SIP 18.