To the Thread Starter :
The relationship with Russia is much more than a mere defence needs. This relationship adds to the weight of India in the world forum. Most of the others apart from France has been time and US dependent. So this strategic relationship of geo-politics is much more predominant factor that just a supplier-user relationship.
The relationship with US is like "Make hay while the sun shines". This is highly time and "US interest" dependent.
If you haven't visited Russia, then you should know that the society structure and the way they think have more similarities with Indians (rather whole of Asia). This is not so with US, with whom it is only business interest.
I had very close look at the different labs under RAS, Sukhoi plants and some of their industries. I have rubbed shoulder with their top scientists. I have fair exposure to US also.
I can say that if India can utilise the wealth of knowledge the Russian labs have, they would be more than enough for keeping any adversaries at bay. This together with India's own industry, Israel's support and France's support, will be creating the best systems in the world.
US systems are fine but their interests vary with time and self need.
As far as I knew, Russians are wary about giving technologies to China as they do not trust them. Again they are also not happy about China's IP violations and reverse engineering.
They would go out of the way to empower India and provide necessary support to groom India which after 50s-60s was not the case with China.
Without Russia's support, India would not have grown so much in Nuclear sector, Space sector, mordernisation of Steel plants, defence systems maturity.
So it is our inability to use the full potential of this relationship. We still want Russia to be the same benevolent USSR with dirt cheap defence systems. We are ready to pay the west more than double the amount we pay to the Russians for almost the similar stuff but crib to pay more to Russians.
India would be too naive if she is thinking that this relationship is only based on defence supplies. It would be too risky for India at least for the foreseeable future.