First time poster, so go easy on the newbie please.

So I have been reading and searching best I can regarding HD HomeRun and see the Prime 3 is discontinued, and can only be found used on ebay, etc. And there is (I hope) a newer Prime 6 device coming out some time in the (near I hope) future.
Does anyone know any of the spec differences between the Prime 3 and Prime 6? As someone looking to possibly switch from a **** Bolt (with spectrum cablecard) to a HD HomeRun, I'm trying to learn about the differences.
Whats the main differences between the Prime 3 and Prime 6 besides I think getting 3 tuners vs 6?
Does the Prime 3 support 4K? Will the Prime 6 support 4K or possibly even 8K? What about connection, network speeds?
I also have a newer Samsung TV. With ****, this is connected via HDMI. There is no app for the Samsung TV, but I think in reading that the HD HomeRun will be auto discovered by the TV as input source? Or would I need to use an Nvidia Shield TV or other device?
I also need to ensure any change from **** to HD HomeRun passes the Wife factor. Can anyone provide input on easy of use in changing channels and recording with Prime 3? Can you use your normal TV remotes? Again, I think HD HomeRun will appear as a normal input on a Samsung TV, so just use your normal remote?
Finally, dare I ask

Thanks,
PT