That is way too true!!
I use my sim only when I'm trying to learn new stunts, other then that it isn't all that real and you can really get into some bad habits. When I first stared to fly RC my instructor installed his Real Flight G-1 into my puter and gave me one little red and white buzz bomb plane that sould spin like a high speed drill bit. He had me fly that plane from one side of the screen to the other and do only one roll. It helped me stop my over controling of the real RC trainer.
When I'm learning something new it really helps me get my fingers working the inputs without doing a lot of thinking so doing a new stunt isn't as hard for me out at the field.
Did you notice I mentioned my instructor set up my first sim for me, the key word was instructor!!