I have been using this Luminous inverter for 5 years. Bought it with the Tata Inva tubular battery. For the first few months it was fine but then there came a problem of loud sound during charging and voltage fluctuations. Lodged a complaint with the customer care and a representative came anf repaired but after a few days the problem started again.
Disadvantages : *Bit bulky and heavy.
* Not that much qualified technicians for customer service.
* Charging is slow.