It's a nice HD video of a flight on a DR-400, clearly showing prop slipstream, and probably some p-factor as well during initial climb, that are common to many GA prop aircraft, and particularly noticeable on a Robin...

 

It's with dismay that I see just two simulators properly replicating this effects, with some special exceptions of add-on aircraft for FSX that can somehow approach the magnitude of the effect, even if doing it through a p-factor scalar only, which is not the most realistic way of simulating this type of effects, but still gives an acceptable outcome.

 

Most simulators will reproduce only torque effects, and cause rolling tendencies, sometimes ending in yaw only because roll induces yaw...

 

IRL as most pilots will confirm, and for this type of aircraft, things happen in a different way, with feet work, and not aileron, being required to counter prop effects under a wide range of flight regimes / situations.

 

http://www.youtube.com/watch?feature=player_embedded&v=aX1aOZpA_30

Just looking at that Ball you know it's asking for rudder, and not doing a roll. Unfortunately the DCS P-51 is way too much aircraft for me, I prefer the more controllable ones!