Cary 805 AE-do they go low?

Thanks George. So in a few words you're saying they would leave something to be desired.
Probably going another route then. Thanks

I currently run McIntosh MC 60s, and softness in the bass, given the potential of the down firing subs in the Definitions is like leaving part of the main course on the table. These speakers don't need the power of the amps to produce the bass, but do need the frequency range at the bottom to not be rolled off.
 
Reaching the sweet spot in regards to amplification will be important, obviously. With all the options available it has become a quest. Been considering this for a while and what conclusion I've come to is that you really have to make compromises. My barometer for satisfying musical enjoyment can be measured in terms of listener fatigue. The Zus can use a bit of warmth, and with a  change as big as amplifier change, would like to hit the sweet spot. 

BTW, much appreciated info here. The Zus have a class D Hypex amp driving a 12" subwoofer, signal taken off the mains. So the signal and it's effectiveness at juicing the Hypex should depend on the linearity of the Carys and not so much on the their ability to control or move air. If I'm mistaken here or missing something. The impedance doesn't drop below 6 Ohms along the FR curve. I can't find damping factor info about the Cary.

Extremely detailed and solid info George. Really good to have knowledgable I must say, experts, on this forum. Since it's few and far between that an opportunity exists to actually hear components, much less in the environment in which we listen, such advice is invaluable.
brf, your input comes from actual listening, so hard to argue there.
I always suspected my next move would be from the older PP MC 60s. Will call Sean Casey at Zu to help as well.

One sand amp that has been used with some success is the Valvet so I'm open to that avenue. 

George and brf- thanks!