Hi
I did this trip in early October 2012. It was a wonderful experience but is very full on. There is a lot of travelling involved with some very early rises. The upside is that you see a great deal. The highlights for me were seeing the Taj Mahal at dawn, coming close to tigers in the wild and sailing on the Ganges.
India is a fascinating country but you should be prepared for the extreme poverty you will witness.
I am considering doing the Kerala trip this year.
Hope this helps you reach a decision.
Lesley