Leben Cs600 and LM 219iA

As a Leben and LM dealer, there will be a pretty decent difference in sound profiles b/t the two.  Both are excellent integrateds.  LM will give you a lot of that SET midrange/top end "magic".  CS600 is a fantastic integrated though.....

Are you looking for something different soundwise out of what you currently have?  Or just looking for a change?

As Charles mentions above, these are two completely different designs.  Probably as much different in overall sound as there are similarities. 

I've never heard either with the Zu's, so really hard to say which the OP would prefer with his musical tastes.  Both would likely be extremely good however.

For ROXY54 -- I'm located in NC. (Lexington area)

Thanks Roxy.  I don't work for them, but know them there very well.  Nice group of guys.