I know few of them, they are present every where, self proclaimed experts.
They called Arjun crappy, Tejas draggy and what not, but when independent agencies do the analysis then results are all different, recent report on Arjun is just one case.
No one is claiming that our products are the best in world, we developed them for our needs and most of the times it met all the user requirements. Yes delay do happen when you develop such a complex technology.......but critics are blind when our users like indian Army or IAF comes with out of world requirement by adding all the best parameters from brochures of different platforms and asking to integrate them in single platform in just one go.
See how many times tenders have not been replied by global venders just because either they don't have such weapons or platforms or are reluctant to supply. Tender for UCAV is one such case.