So I got my Roamio Sunday night and got it set up and going on Monday. I did run into some interesting hiccups with the Minis so thought I would share the experience.
My Mini setup is pretty typical, I am using MoCA hosted by the main TiVo, which has ethernet connectivity directly to the rest of my home network.
So, here's how things went down.
I got my Roamio setup and activated service on it, and I then disconnected the XL4 and put the Roamio Plus in its place. I connected Coax and tried to connect the Minis.
The Minis could see the Roamio on the home network but could not connect to it (infamous V70 unauthorized message). I suspected that the Minis needed to phone home in order to determine that the new Roamio was authorized for service. When I tried to do a "force connection to TiVo" in the settings menu of the Minis, they had no gateway to the outside world as the host XL4 (which acts as their gateway) was disconnected.
I re-connected the XL4 to coax, disabled MoCA on the Roamio, had the Minis phone home, this time they recognized that the Roamio was authorized on the account. I was then able to re-enable MoCA on the Roamio and connect the Minis.
So, these might be the easiest steps to perform if you are swapping out your XL4 for a Roamio and you use MoCA with your Minis;
1. Activate service on the Roamio and make sure it has performed all updates and phoned home. Make sure it shows authorized for service in the status screen. Do not activate MoCA on the Roamio at this time.
2. With the host XL4 still connected, initiate a connection from each Mini to the TiVo mothership to get account info that shows the new Roamio.
3. Disconnect Coax from the XL4 and/or turn off the MoCA bridge function.
4. Turn on the MoCA bridge on the Roamio.
5. On each Mini go into settings -> cable cards -> TiVo setup and choose the new Roamio as the connected DVR.
You might want to verify it's working with the new TiVo before wiping out the settings on your old one. Another option I suppose would be to reset everything on each Mini and simply set them up from scratch with the new Roamio.