Its a fantastic product that does the advertised job really well. I have a 875 VA unit bought in april 2014 and since it has been working flawlessly I got another one for my parents place in september 2014.
The fact that I got a second unit(improved one, named Zelio, 900 VA) is ample proof that the faith in the product is very high. Works perfectly during powercuts - in fact except for the sound it makes, we dont even know the power is out!
I have paired the unit with Luminous 150 AH tall tubular batteries(LT500). The product is neat and handy, and very easy to install.
Will definitely recommend the product.