You need to use Boot Camp!
Seconded!
What i mean is...
Its almost like the flightsim doesnt take into consideration drag? , If i fly level at low speed(close to the stall) and go to a seriously high climb angle, it will do so instantly , no lag , no drag , no bogging down , nothing. That isnt realistic!
X-Plane calculates drag based on airframe components and power based on what the designer of the airplane designates. It's the only retail flight sim that I know of that does this. And X-Plane as been certified by the FAA. That means something. I used to fly a DC9 (a real one) and took an X-Plane DC9 on a cross country trip and it's performance was very realistic. Now there are thousands of aircraft out there that have been designed by individuals who could have been unrealistic in their power designation or created fantasy planes.
The best way to test this is see if you can find a WWI aircraft modeled in X-Plane and try your maneuver. If you don't stall post haste, then I might agree there are some holes in the flight model. The other possibility would be to email the X-Plane author, Austin Myer at X-Plane.com.