I used this technique on my latest mix.  It's a long video and worth watching, but the short version is that by using two instances of EZD2, the author, Eric Tarr, better controls which kit pieces are wet/dry and it's much easier to fine tune the drums.
 
He uses a third instance and loads a different snare drum in it to alter the original snare kit piece.
 
He also buses the synth outputs and uses parallel compression, etc.
 
It's a pretty slick method.
 
https://youtu.be/1eI8RZrAqzQ

A LOT EASIER TO JUST USE SUPERIOR DRUMMER for this kind of thing...
build kits with Xdrums.

I know SD is Toontrack's premier product, but I don't have it.  Of the drum programs I do have, Session Drummer, Addictive Drums and EZD2, I use EZD2 the most.

I had no idea EZDrummer was that restrictive. Even Session Drummer lets you build custom kits.
 
Of course, that doesn't make the technique any less slick. I do it all the time, despite having Superior Drummer as my main drum sampler. But I've never needed to use two instances of Superior; the second sound source is usually Kontakt, Jamstix, TTS-1 or a synthesizer. 
 
Another technique for percussion variation is to automate effects. My favorite thing to automate on drums is parallel distortion. For example, bring up the distortion on the chorus and back it off for the verses.

bitflipper 
Another technique for percussion variation is to automate effects. My favorite thing to automate on drums is parallel distortion. For example, bring up the distortion on the chorus and back it off for the verses.

You can create custom kits, but you can't customize the Fx for individual kit pieces.  That third instance of EZD 2 is to add another snare with a complimentary tonal quality and blend it in to shape the original snare sound further.
 
One day I may splurge for SD 2.0/3.x, but for now EZD 2 works well for the Americana/Folk songs I write.
 
Thanks for the tip about automating distortion.

Hey olemon, you could always do what I do using ezd. I use an instance for each group. Lol! It sucks creating it for the first time, but after you create it the initial time you can save it as a template and it loads right up. For example, I'll use one module for kick and snare, another for hats, one for toms, one for crashes and one for ride.
 
That said, ezd 2 has improved things drastically for the better and if you own certain kits, you can use their template that comes with them. For example their latest metal kit gives you individual Tom channels and control instead of single's. If you use the template for that and remove all the sounds, you can use the sounds you have from the other libraries. 
 
If anything, get their latest metal kit just for the mix template that comes with it. It gives you a lot more options than the other kits for creating virtual tracks in Sonar. Good luck!
 
-Danny

Thanks, Danny!

olemon
Thanks, Danny!

You're welcome. Just to show you how out of my tree I am, this is what I used to do with EZD1. LOL!
 
http://www.dannydanzi.com/Media/EzdHybridExtreme.jpg
 

Uh, dang:)