To answer a few questions. I got the sim because the one which comes with it only works on win98 2k and maybe xp?. RF5 supports Vista and Windows 7, which I happen to have. Besides I can't open the box yet remember. So having the software wouldn't do me any good if Ididn't get to use it. I won't have any issue with tuning the 2stroke engine. I've been around engines my entire life as my dad was a mechanic for over 20 years. Besides that though I was reading that this plane comes all setup with the engine proofed anyhow. So the site says. Which was the difference in the OS 46fx and fxi I thought is that this engine has the kid proofing on the engine settings so you basically can't mess it up. Is there anyway to check the trims before takeoff to get them pretty much dead on? Again I though this plane took care of the trim stuff as well, but maybe not.