I recently picked up the Usha Spectrum 25L model, being impressed by the fully copper tank unlike the steel ones in the others.
It looks pretty good but there are better looking ones. But anyway looks are not that important in this segment....its the performance that matters.
Copper or not, the water is just not hot enough. Dont get me wrong, it heats water alright, but if its a very cold day, the water is not hot enough. And once hot, it loses its temperature pretty quickly - in 2-3 hours. My 1.5 year old Racold on the other hand keeps it hot almost for 6-8 hours! This raises doubts about the design and quality of insulation used.
The fit is not that great either. If you look at the bottom part(where the LEDs, connections are) you will easily understand what I mean. The Racold is so much cleaner and neater in appearance.
All in all I recommend you go in for the Racold Eterno which is available at the same price.