Great value - it's not often that Apple give something away like this.
For me, the only problem lies in recording output from MainStage (I only have GarageBand, not Logic). The reason I want to do this is that not all of the patches are in a format that is usable in GarageBand.
Most of the Jam Pack loops use the aif. or .caf file extension and are available in Garageband, but there are a significant number that use a different file extension that can only be used by Logic. (For example the Suitcase electric piano.) I tried using SoundFlower to route the output of MainStage into GB, but got bad latency. If I could just play a MIDI file through MainStage everything would be perfect, but I can't work out how to do it.
I could just buy Logic, but apart from the expense, I'm told that there is a big learning curve progressing from GB to Logic, which puts me off.
Has anyone got any bright ideas about how to play a MIDI file through MainStage without using Logic?