XG1v4

If that’s only drawback; then I’ll switch out the old system to the new. I guess I need to get two Xi6 boxes. If I don’t like it, I can always change back. I hope the rental on the new equipment the same price 

Xi6 is wireless and requires the Xfinity router.  Recordings are in the cloud, as it's not a DVR.  Xi6 supports Dolby Vision while the XG1v4 does HDR10, but not DV.  

Xi6 requires Xfinity router if it is the ONLY 4k box on the system.

I do NOT have an Xfinity router, but have other (wired) 4K box, as well as the Xi6 and everything works great.

The CLOUD restriction on the Xi6 is not longer an issue for me as cloud recording fully support 5.1/atmos audio, previously they were limited to 2.0 stereo only

It's possible that having one wired XG1v4 means the Xfinity router is not required.  I recall that when I first got 4K, Xfinity said I had to use their router with the Xi6, which is one of the reasons I sent with XG1v4 instead.  Of course, that could have changed in the last few years. 

I was under the impression (and corrected by the tech that came to my house to fix DVR issue of having 2 4K dvr's fighting each other) - that any use of Xi6 needed Xfinity gateway.

I am proud to tell you that is not true , at least in the case of me, who does have the XG1v4 in the house as well