Is the Leben CS600x unbeatable?

Depends on how much money you have to spend. I think you need to do some auditioning. Don't rely on ads or faith. There are many fine integrated amps out there. The LEBEN does have a good reputation but rather limited sales, in order to get much reviewer and customer feedback. Especially if you are buying on faith.

In the tube-based category I would take a strong look at PRIMA LUNA. Especially when it comes to price vs, build quality, vs. circuitry sophistication and true musical performance. Check it out and you will see what I am talking about. Also, the flexibility is unbeatable.

I would love to run the O/96 with my Decware Mini Torii.  Heard the speakers at Aural Audio in Denver, not sure what was driving it but damn :)

“My point is, if you have the Leben but have the resources to upgrade…what’s the upgrade?”

@gochurchgo 

Accuphase E-700 or E-800S. 

The synthesis a100 titan is awesome on devores with enough power to drive any real loudspeakers and it  has an outstanding built in dac 

DAVE AND troy

AUDIO INTELLECT NJ

synthesis dealers 

"In the tube-based category I would take a strong look at PRIMA LUNA. Especially when it comes to price vs, build quality, vs. circuitry sophistication and true musical performance. Check it out and you will see what I am talking about. Also, the flexibility is unbeatable."

axpert-That would be an interesting comparison, but I'm thinking since Leben is maybe on the Shindo Japanese "boutique" level, owners may scoff at the idea of comparing MIC/value gear?

The OP's Devore O/96 would probably sound fantastic thru the PL EVO 400.

There's always a few listed here and the other site, so that means a buyer has leverage to negotiate.