Fully agree with Tom. Shape and airfoils are only pieces of the puzzle for a good flight model, and more or less only affect aircraft performance. Of course they have an effect on other areas, such as stability as well, but in order to get the "feel" right, one has to do much much more. Tom mentioned custom radii of gyration or cg location. This is very important to work at. I have seen freeware and payware aircraft, where these areas are left at default or just in the right ballpark, making the aircraft handle like a radio controlled aircraft. High roll rates, almost no lagging motion/intertia in roll, pitch or yaw, killing all the fun. Not placing and tuning the cg correctly can also create very weird and unrealistic behavior. For example, fly at a low speed and yank back the stick. Of course you wouldn't do that in the real aircraft, but I use this test often in order to see if the control power is realistic. Flying at low speed, close to stall speed, and yanking back the stick often results in AOAs of 40-50 deg or more, which is completely unrealistic. For some aircraft that might be correct, for most it is not. In real live, the aircraft elevator would not be in the position to create such a pitch up motion at low speed, due to low dynamic pressure and loss of control effectiveness at higher AOAs. This is often due to a wrong cg placement, a wrong pitch moment coefficient of the airfoil or a combination of both, but could be easily corrected. From my point of view, Planemaker is doing a pretty good job, but does not necessarily give you all the control you need for specific parts of the envelope, or if you really want to represent the personality of an aircraft with all its pros and cons. In order to go the extra mile, one needs to take care of it by coding plug-ins, which give much more control. However, you have to know what you are doing and you have to have the knowlege about what needs to be changed, tweaked or controlled dynamically via a plug-in, in order to create a certain effect or a certain behavior . For my aircraft, I am overriding the complete flight controls and big parts of the engine by a plug-in and I can basically re-create any effect or behavior I want to see or I want to be simulated. I can change control surface effectiveness, supercharger behavior, control surface buffeting, engine gyroscopic precession, engine corkscrewing slipstream, transsonic effects and much more on the fly and exactly how I want it. I more or less have full control. Does it sound cool? Yes! Is it easy to do? No. It's a lot of extra work, needs proper testing, creative out of the box thinking and hours and hours of research and coding. ...but it is also no black magic. Anybody could learn how to do it.