I have one and everyone should, even a short blip can cause serious issues to your computer. I have a basic home grade one for my PC, it's an Ultra. Gives me about 25 minutes or so, since I put new batteries into it not that long ago.
For my network/server equipment I have a Trippe Lite inverter-charger connected to 2 large 100AH 12v deep cycle batteries. It gives me about 5 hours or so. I have 2 more batteries that I will be connecting to it once I build my battery rack and finish my basement. Occasionally we get extended maintenance power outages because the main road near here gets redone every 2 years or so and they sometimes replace the poles.
Eventually I want to setup a proper -48v dual conversion setup. Though I'm afraid that may cause more strain on the batteries from being charging all the time. Though I think if it's kept at float they will never boil over so I think I'd be fine.... I need to research this more. Finding rectifiers is hard too, none of the dealers show prices or offer an option to buy.