I have been using Intex UPS from past 10 years and I am really very satisfied with the overall performance. The battery backup is really awesome.
Earlier I was using my desktop and I was able to use my computer for about 45 minutes after power cut. One drawback is that it makes a lout of noise like beep. If you are listening music or watching video then that will disturb a lot. Overall it is one of the best UPS available in the market.