I think you didn’t get an answer because you posted to the wrong forum. This is the EZKeys forum.

I can tell you that in the full version, the default modern/vintage sound pack has 3 drumkits (DW, Gretsch and Yamaha), which have been mic’d, processed and mixed in different ways to give you 29 distinct sounds/styles. On top of that, you can replace single drums with ones from the other kits, and also change the mixer settings. You might not be able to get the exact sound you’d like for each song you write, but you’d be able to get something in the right ballpark. Having said that, you may hear a sample from an expansion and say to yourself, ‘Man, I have to get that sound. It’s exactly what I had in mind.’

Personally, if I was only going to get one or two other expansions, I think it would be either ‘The Classic’, or ‘Alt-Rock’ (Steve Albini!). But it really depends on what kind of music you’re into. Those would be useless for Metal, for instance.

Is EZ Drummer worth it? If you don’t like programming drums, but you do like song writing and recording, then I think EZD will make your hobby more enjoyable by eliminating a slow and painful task.