Sure. Even sitting with a transmitter in your hands turned off and imagining flying a model can help your skills. In fact, that was my homework assignment when I first joined a club and took their flight school. And also to familiarize yourself with every trim and switch without looking down.

Will it give an exact and interchangable experience of what the "real thing" will be like? Nah. They are getting better. I have Dave Brown's RCFS 2001 and FMS v2 Aplha 8.5. The Super Skybolt and Sopwith Camel in the FMS are both fairly tough to land smooth, and will stall and snap in unrecoverable fashion at low altitudes, and I like to practice with them. Some models can do things like inverted flat spins with the throttle cut to idle that gain altitide. And I never find a divot of pothole on the rundays like I do at our field. I think it was Real Flight version 3 or 3.5 that we had at our mall show last month. The Corsair allowed us to take off with the landing gear up. That's not gonna happen in real life. I was also zipping a helicopter around and impressing the teenagers who wanted to see one fly. I have no helicopter skills and don't believe for a minute I could keep a glow R/C helicopter alive for a single flight.

Just remember it is practice and does not mean you're able to transfer the abilities directly to an R/C model. The "fear factor" is just not there with a sim, and the pressure to fly and not screw up in front of your peers caused a lot of dirt naps - as does excessive testosterone in front of those same peers.