Never used Ninjatrader.
But have heard much about the demo being close to real market conditions.
You think those are similar?
Thinkorswim by TD Ameritrade supports mac, as does TWS by Interactive Brokers. If you want something generic for Mac, MotiveWave is probably your best bet unless you run virtualization software.
Just install window VM. we ran stats and Ninja on Mac in virtual VM performs faster than Ninja on Dell. Ninja is the best software I came across. Cheap, fantastic and amazing support.
used it for over a decade. Plus full power of c# to code what ever you want. Free unless you trade live.
Would you use it live instead of a brokers platform?
This is who I deal with
https://www.generictrade.com/technology/