Roamio Plus and Roamio OTA on the same network

So, I'm thinking about purchasing a Roamio OTA for when I finally cut the cord (have Fios TV right now). I currently have a Roamio Plus and 3 Minis.

If I get the OTA now....what would be my functional situation between the OTA and Plus models?

I'm guessing the following:

* OTA box can "see" the recordings on my Plus box and play them....just like my Minis
* Plus box can "see" the recordings on my OTA box and play them
*OTA box (and the TV hooked up to it) can only use the tuners in the OTA box for live viewing

I don't think the OTA box can utilize a tuner in the Plus box and show it locally, like a Mini. Right?

Anything else I'm missing? Am I right?

Thanks, Mike