I use both Oanda and MT4. The only reason I have downloaded MT4 is that I can test systems on it. With "F12" you can scroll 1 candle at a time on MT4, and that makes testing much easier
But otherwise you can get Oanda to look the same as MT4 platform.
I don't know if you know, but it is possible to change colours on oanda platform..
Sorry for my English, but I hope you understand what I mean.
I attached 2 screenshots for comparison between Oanda and MT4 graphs.