Sibelius' playback of grace notes is often unacceptable. Sibelius plays back all grace notes as acciacaturas: i.e., before the beat and very quickly. I find the only way to get appogiaturas to play back correctly as they would be performed by informed live musicians is to notate them rhythmically as regular notes, possibly with an accent mark. Visually, that negates the intention of the composer who wanted appogiaturas notated as grace notes. This is an important problem thst should be addressed.
Idea No. 271