Interesting that you are considering moving to Rogers when SO MANY people are talking about leaving Rogers BECAUSE of the terrible interface that has been tested in some areas on the Nextbox 3 PVR.
Before you make the decision to change, you should read some of the 1,523 complaints here: New Nextbox Navigator - Rogers Community
The Rogers PVR interface has been described by people who have used other companies PVR's as the WORST there is. The Nextbox is fairly unreliable with bugs and problems that are NOT being fixed, and the interface is being changed to the UNIVERSALLY hated Navigatr. This month it will be rolled out to all of Ontario. NOBODY likes it.
And most importantly, Rogers 4K boxes will be using the new Navigatr interface. Rogers has a 4K set-top box available now - but it is NOT a PVR. The Rogers 4K PVR comes out mid April - and will run Navigatr.
There isn't much 4K content available. Search the 4K thread on the Rogers forums for a more complete list of what's available.
I would recommend you wait and get your 4K from Netflix and some of the other streaming services. I've been researching them myself. Several are US based - and to get them you will need to get an American credit card and give them a US address and then 'spoof' your location using a VPN to trick the streaming service into thinking you are located in the US.
There are a bunch of streaming services that are starting to offer 4K content. It's worth it for you to do a little research before you (make a possible mistake by) choosing Rogers.
To summarize - the Rogers PVR is very, very poorly designed. But if you can stomach an unreliable box that is hard to use, and was designed by idiots, then you can have access to some 4K content on Shomi (which will soon give access to some of the 4K content that is on Netflix).