I prefer to use one UPS per computer, although I accept the practice of having two system to one UPS IF-- the UPS provides sufficient wattage, and IF -- you have the systems in the same location so that you can shut down one of the systems manually during an outage (at least when you're at home). In that case, I wouldn't leave the second computer running when away from the house.
To clarify, most of these units do not allow for a communications link with more than a single computer. If they do, they require purchase of a ~$150 accessory that fits inside the UPS with a rear-panel port-presence for Ethernet communication.
For other equipment, like XBOX or home-theater systems, I don't think you can do any "smart UPS management" or arrange for the equipment to be automatically shut down with an outage. So like the 2PC/1UPS example above, you'll need to be present for manual power-down. You don't want these UPS devices to discharge completely: it shortens battery life noticeably.
Also, my one firsthand experience with CyberPower was unpleasant. It wasn't compatible with my computer's Seasonic PSU. What kind of UPS company would fall short with that kind of limitation? I've had TrippLite, Belkin, CyberPower and APC. I now prefer APC models -- exclusively for the time being.
I know one electronics tech whose monthly Social Security is a limitation, and he only uses surge protectors. I just think such an approach is inadequate. UPSes are an insurance policy, and I haven't lost a piece of equipment to a thunderstorm or other electrical interruption since I started using them. I've never corrupted a drive or lost data since I started using UPSes. All of my equipment seems to have marvelously long lifespans.
So here is an option. You can buy refurbished UPS models that are twice as expensive new, and get reliable battery replacements at the same place:
Refurb UPS
I also think they sell new units. Check 'em out.