I’m debating on CMC, but I want to be sure I know what I’m paying for first.
Leaving aside all of the marketing, it looks like CMC does two things:
Removes the 5-minute cooldown between captures, and
Removes the 12-second limit on clip length (i.e. It records until motion stops, no matter how long that is.)
Is it really just that simple?
Information from the Support Pages
It is a monthly payment of $1.49 per camera using CMC.
Many of our users asked for a way to extend the 12-second motion recording already included with Wyze Cam. While installing a microSD card helps solve this problem, these videos are stored locally and not in the cloud. This can be problematic if you want to access or retrieve event videos after your Wyze Cam has been unplugged or stolen. Complete Motion Capture solves this by saving event videos directly to the cloud for easy access.
So, “Yes”
Yes 
If you already have microSD cards and use Event Recording you already get local clips as long as motion lasts, but this stores them in the cloud. Removing the 5-minute cool down is the real selling point IMO. I use it on only one camera at the moment and it’s very convenient to tap the notification and get the full clip.
Also it may be of value to store imagery in the cloud in case the camera is stolen.
In a nutshell, yes to both question, it’s a more convenient way to look at clips of movement.
Try it out on 1 camera - I will say that the motion capture is too sensitive; I end up with a bunch of blank videos…