I would say that on a non instrument level it can help a fair bit in that it will get you used to the basic principles, especially if you have a stick and rudder pedals and will give you a small headstart but is not really something you could learn to fly in.As the other guy said, it could help learning on instrument training. By the way im talking about widely availaible sims her: MS fs etc.....not some great big concorde full cockpit thing