McIntosh C12000

Not sure what you mean. On their website they provide literature on the product, with which you can see any and all changes. After comparing the literature and then the specifications, there are virtually no substantive changes aside from the new handles, the small change to the phono section, and the ability to either send signal through the tubes or through solid state (cool feature unto itself). I may reach out to see if there are other changes that they chose to not mention.

What else is needed? 

It's only 2 chassis vs 3, has handles, and configurable phono for either MM or MC cartridges. The phono change was vastly different from previous versions where both phono inputs were fixed without variable settings to match a wider variety of cartridges. I personally like the look as it matches my amps. 

I like the look also.  And. if the phono stage changes were that significant then it is worth it for vinyl heads like me.

My only gripe is,  why are they still using computer style ribbon cables to connect the 2 pieces?  Surely there must be better options like the cables Modwright used for their power supply connectors on the Oppo Mods.  Doubtful it is that much better than my C2500.