All these sites offer you the standard features that a charting system demands: candlestick vs. bars, indicators, moving averages, etc. For performing Technical Analysis (TA) this is useful, but so is OKCoin's future platform charting. So don't be scared to use native charting apps that exchanges offer.
A little known option is also Coinorama, a great site that lets you compare different exchanges on the same graph, view relative price, and more.