It definitely depends on who you are, how you understanding of racing is etc.
Of course, LFS will make almost anybody better at driving an everyday car, but when it comes to pushing the limits and driving the car on the absolute edge, it's a different story.
I have always been quite fast at adapting to cars and tracks in LFS, and I especially have a flair for the formula cars. So after two years of sim-racing, I decided to give it a go in the real world last summer. I signed up for a Formula BMW license course in Valencia, and even though I didn't get through to the next round, I could definitely feel the influence from simracing.
I had no previous experience, but I could maneuver the car around easily, keep up with the other drivers and even catch up with them.
I still believe that the reason I didn't go through to the next round was because I was not mastering heel-and-toe, which was essential to be the fastest. Cornering, lines and stuff like that was good, and I can only thank simracing for that.
And learning heel-and-toe is just a matter of getting a clutch pedal, which is what I am currently aiming for.