I guess I just find limited use for a higher fidelity simulator, because no matter how good the physics engine, modelling, and the controller interface is, it's still not going to translate to the real-world exactly.
I use a simulator mostly for the following:
* Get a rough idea of the handling characteristics of a particular airframe - flying wing vs three channel high wing trainer vs 4 channel warbird vs gliders, etc. I think even that basic web based one approximates those pretty well.
* Get used to the orientation differences between tail in vs nose in flight, inverted, etc.
I do run Phoenix, in a virtual machine running on linux machine running the native kvm virtualization features of linux, where I setup a Windows 7 guest. It runs ok, but I can't get full graphics support and there's lag/stutter.
With Phoenix, the benefit of having that with a TX interface is that I can also experiment with different TX configurations to see how it would vary with the same plane. So, I'm able to play around with spoilerons, differential, etc before I actually launch my plane.
If that's what you're going after, then yeah, I would go with a full on sim... otherwise, I learned to fly with a free sim (Absolute RC Simulator) I downloaded to my Android tablet and used the touch-screen "virtual sticks" to fly. I only bought the Phoenix software with the interface from a friend who decided to switch to RealFlight, and sold it to me for $20.