I have been regular buyer from ebay.in / Futurebazaar / seventymm / babyoye / yebhi / yepme etc. and I am Happy to rate Flipkart as No: 1 site, they do not waste your valuable time by delaying orders. Personally I can speak only about myself, as I dont know who faced issues with Flipkart. Till date I did not have any issues and all items were received on the given timeline.
Cons: Very less variety of products, Mostly out of stock.
Other than that you can trust this site completely, also they have their own courier for shipping. I was All The Best To Flipkart Team and keep or make their service much better, and not become like other shopping sites. Cheers!