If you are about to buy a cooler, there are a few things you need to check before.
1) Where do you live? Air coolers work well only in the places where humidity is low, for example Pune (where I live), Rajasthan etc. Look up your newspaper and find out the humidity level in your town. It should be less than 50%. Coolers wont be of any use in Madras, Calcutta etc.
2) Your room is smaller than 100 sq.ft. Cooler is not an A/C. It has low cooling capacity. Dont expect the poor machine to cool down the temprature of a big room.
3) The cooler should have large area for effective evaporation of water. Those slim tall models are no good. Go for rectangular box type model with large back like Symphony Ninja has.
4) It should have large water storage capacity so that once filled it can run continuously for at least the whole night. Symphony Ninja can hold 13 litres of water and its quite sufficient.
For Symphony Ninja and me, all these parameters matched perfectly, so I bought it. (about a month back) And Im quite satisfied with the little fellow.
But life is not bed of roses. The machine has some drawbacks too. If you try to move it from one room to another when its not empty, itll surely leak. Secondly, the power cord is too short (hardy 5 feet) and so extension sockets are needed which screw up the aesthetics of ur room.
But apart from these minor shortcomings, Symphony Ninja is cool! Its price is also cool, Rs. 3200/-
Happy summer time...