I've found that the wind and turbulence has something to do with all that.

It felt like the airplanes in the sims I own all stall too cleanly until I made sure that the flying field had some wind or turbulence. Some of the sims launch the flying fields with no wind set. Set some wind or turbulence, and a lot of the "un-natural" behavior goes away.

It really seems that the default for every sim would be at least 5mph and bumpy winds, but it seems the developers don't think that way.