I purchased this Bajaj 1500W immersion rod couple of weeks back and I would say it is very easy to use.
The design of the product seems to be quite good and it capacity of 1500W helps in heating a full bucket of water to a decent hot state in a matter of 10 mins.
I have followed the instructions of the manufacturer strictly in order to avoid any issues. I feel it is better to clean the heating element using a mild detergent / vim liquid to clean of the hard water scales which forms on the same. By doing this you would be increasing the life of the coil and also reducing electricity wastages.