Canard : CMMR is the ability to supress noise from the power supply - its not a complete description of a streamers SINAD performance .0
You do a little false all I'm afraid .. a "plus" and its AKM will be around '113-114db' in SINAD 1K with its 5534 output (for -115db it seems ultra). it is first due to the limits of these chip akm and ess ...;-)
in the case of the "plus" these 5534 (which has equipped most of the pro machines from the 1980s until very very recamation..) we can imagine that for a cost story....
(will become sensitive by cascading these output AOPs....otherwise on just a 5534 facing a 1611...you risk being disappointed by the differences observed on just a sinad 1k )
;-)
A ne5532 will show very good results with a noise free powersupply , almost as good as an opa 1612 with the same supply. In this case a high CMMR doesnt matter.
But with a bad powersupply - the opa1612 will show a 20 dB better result than the ne5532.