Hi, if all I'm doing is using it for is 480i through 1080P Live TV , is there any need to go with the 4K over the older 1080P "HD" box?
I won't be using it for anything other than Live TV (ESPN+ and HDHomeRun OTA).
I guess what I'm asking is, other than having a faster GUI that I'll never look at, is there anything the newer 4K devices offer that I might be interested in?
Also, I require 24/7 constant on. I don't want the device going to sleep or throwing up a screensaver.
Definitely go with the 4k. Never invest in 9 year old technology. Plus there have been reported issues with the slower processor causing issues with channels deinterlacer.
Always on is not an issue, not a default setting but easily changed
Having had both, it's a no-brainer. Unless you get an HD for free, don't bother.
I agree with the above advice. Faster ethernet and (much) better remote too... pay the extra for future proofing, you won't regret it. There will be updates and surprises ahead and tvOS improvements that will benefit you. For example the latest AppleTV's can display FaceTime calls via iPhone camera and live vocal stripping in Apple Music for impromptu karaoke! Lol, OK maybe those don't interest you at this time, but my hunch is there will be others 
I agree with the comments above. I still have an old ATV HD from 2016 in my garage it is showing its age with the latest TVOS updates.
A 9 year old Apple device that still gets OS updates is RARE. I wouldn't be surprised if it didn't get tvOS 18 in the fall.
The only reason it probably still gets tvOS updates at this point is because they don't really even do anything to tvOS each year 
Definitely don't spend any money on the 1080p version.
Thank you. I ordered a used 32GB 4K second gen.
Also, for others reading this, don’t forget the latest Apple TV 4K (w/ USB-C remote) is fanless. So consider that older 4K (w/ lightning remote) fan will die someday.
If you buy new, you get 3? months Apple TV+ included.