In case you missed it, even without official support for helicopters, FlyInside is digging into developing the first payware model for Microsoft Flight Simulator.
And yes, FlyInside is promising a good, advanced flight model as well:
The Flight Model: Although MSFS does not currently include a helicopter flight model, FlyInside has had one under development for years (for FlyInside Flight Simulator). Our flight model provides an authentic helicopter flight experience, with realistic collective/cyclic response, ground effect, flap-back, transverse flow, torque/yaw, and auto-rotation capabilities.
For those of you with helicopter flight controls, our 47G has a piston engine simulation, with manual throttle control. For those running a normal joystick, you can also turn on the auto-governor and fly using 4-axis control only.
Expect some more news (and a video with my opinion) as soon as FlyInside has a build ready for previewing. Meanwhile, check out the update post on the official MSFS forums (you will find some more screnshots there as well).