I like how they focus each version on some aspect this version is voices, and such, would be cool if the next version focuses on instrumentation and melody construction and a bit more on the technical aspects.
With current models needs to be structured and the melody needs to resolve, it is very hard to mix two tempo's, variable tempo is another thing that it struggles with. Setting timing when an instrument needs to kick in how long a specific intro, break needs to be. It also really struggles with ambient tracks with spoken words it always want a melody or instrumentation, has a hard time with spoken words.
Still lots of aspects where it still falls short.
What I do like is mashing different styles together, it actually does it very well, a small problem I found is if you mix style sometimes have a hard time sometimes keeping the dominant style front and center, Like jazz grunge it would sometimes lean to heavy into the jazz and it sort of loses focus.