The unit is a bit on the large side but seems to work well. Personally, I'm using it for low power devices like network switches and DSL routers, which it will keep running for a fair amount of time. Purpose of my use is to use these to keep the house communication systems running, rather than a PC and monitor.
I have two and they've so far performed very well. The only annoying thing is the inability to tell the unit not to beep; if I am out when the power gets cut, the neighbours can't stop them beeping. They really could do with a switch for this as if the power gets cut, I'll know about it by other means.
No way to inform other devices (such as a PC) that the power has been cut, but as I'm using this for solid state equipment, that doesn't matter to me.
I found it better to use the moulded screw head slots to mount these on the walls rather than leave them on the floor. I also find the protection sockets handy just to give that extra protection to equipment that I don't want backed up.
If I were to suggest a design improvement, I'd say a dedicated socket that only gets powered on if the power does get cut; so something like a low-power light in the office could be turned on if the power gets cut; especially as one of them is in with the distribution board.