The initial question was specifically about the realism of the physics in simulators. IMO CSM is still very good in this particular aspect. Many of the newer simulators have better graphics etc but worse dynamic flight models. FMS is an example as is the Ripmax Flight Sim and Easyfly (all IMO).

I personally would never buy a simulator that didn't allow me to set up my own models fairly easily. Several fail on this aspect including RF G2 which starts off expensive and then charges extra for every update.

From Fliptunes original list I'd probably go for Aerofly Pro but I've only played with it for a short time so I don't know how easy it is to break the flight model.

Steve