A similar model protects my PC (Back-UPS1500 + extra battery). It is perfectly sufficient, and gets me through power cuts of over two hours without having to shut down.
On the other hand, my small Back-UPS500 (small and old) will not keep my Cyrus amp powered on through a power cut! It is more sensitive than a computer! The cassette deck and cd player keep on playing, but the amp shuts down. I have not tried it on the bigger, newer BACK-UPS1500 as they are too far apart.
If it suits the equipment, it suits. If it doesn't it doesn't. I have a Belkin surge protector for the amp+etc --- but it would be nice to have a UPS too.
contentedbloke, sometimes, with our Chennai voltages as you mention, the UPS cuts in, and the low voltage goes on just too long for the UPS ever to get charged. If I am to go on working (err,
working? ) I have to give the UPS enough voltage, and I keep a stabiliser handy to do that. Glad to say that it hasn't happened for a few months: the power situation back in the summer was so bad I nearly bought a generator!