Any advantage or not using Orderflow / Delta indicators?

Thanks

Of course if you are designing HFT momentum scalping algo's, probably not if you're deciding whether to buy a stock or commodity to hold for the next few weeks or months.
For different timeframes inbetween some people use orderflow, others swear everything is in the chart.
Lots of free indicators available for Ninjatrader, why don't you try them and see whether any are useful to you ie. Anybody I have read about who is anywhere near successful at this has spent a lot of time working things out for themselves and been prepared to do that work themselves.