The simulators relay information such as ball flight, launch angle, trajectory and distance. So you can judge the performance of clubs, before you make the purchase. And if a store lets you to test a club on a course outside the store, take them up on their offer. So you think you found the perfect clubs, but you are either too tall or too short for them. Most stores can fit your clubs to suit you.
Crane considers club-fitting an integral fundamental part of the game.
Whether or not a club fits properly will have a direct impact on your game. So don't hesitate to ask to change everything from a club's length to its lie angle and grip as per your needs.