The Hot Start Challenger 650 is the most detailed aircraft simulation in any sim platform. Very few VAs have it in their fleet, so Simfly could stand out if it offered it.
Take Command!: Hot Start Challenger 650, X-Aviation
I’ve never heard of this plane, I’m just seeing it now
It’s amazing. Everything, and I mean everything, is simulated accurately. For instance, the GPS signals are dynamic and can fail randomly in parts of the world like the Mideast or South China Sea due to radio signal propagation (which is itself simulated) from jamming stations and terrain masking. The plane itself is not that difficult to fly or program, but there are no shortcuts to following the correct procedures. Also, it has its own FBO where you begin the flight and perform a walk around so the immersion is great.