I am shopping on Flipkart for about 2 years now. Its amazing. If u have any problem with the product u can hit the return replace button. Within 48 hours you will receive a call from their customer service and they will forward your request.
They will pick up the product and refund or replace accordingly.I had this experience with my kids t-shirt. They were a bit tight. But flipkart replaced it within a weeks time. Their service is remarkable.
Almost all products are good. Again it depends on how the merchant is.
But overall my experience has been good.