I am a satisfied customer of Flipkart. From the past 3 years I am using Flipkart for all my online purchases and they always delivered the order before expectation, its really amazing.
And what I liked most about them is I ordered a gift for my fiance on her bday, she was residing in Haridwar and amazingly they delivered at the exact promised date and that was on her birthday. She got so surprised and I enjoyed her joy.
But nowadays there is delay and some time cancellation in third party items. So, take care when ordering, if the item is provided thru some third party then there is a chance of delay.