Sure... I have other UPSs around the house and at work for computers. The idea was not to run off it for any extended period of time, it is to avoid hard crashes. But the batteries will go bad no matter what, most only last about 3-4 years, even with minimal use.
FPL frequently has these momentary little blips that last under 3 seconds, often under 1 second. The only time I lost power for a long time was during the NFL playoffs, Packers vs. Vikings, coldest day past winter, just before the 4th quarter. FPL power went down for 18 hours. I missed the entire 4th quarter, and the overtime. By morning, temperature in my house was 45 degrees F. FPL had to replace the transformer for our neighborhood.