You really don't need to go pay a bunch of money for sim prep. The best thing you can do is make sure you intrument scan is really sharp on a regular steam guage panel. The sim they use has steam guages on the left and a PFD on the right. They let you choose which seat you fly from. Most choose the steam guages, even if they are used to PFDs. This is because of the sim set up and where the various knobs and buttons are located. The non flying pilot can twist and turn them a lot more and easier to help the flying pilot more from the right side while you fly the left. They definitely watch your CRM also- so work things out with your sim partner the night before (they will tell you the exact profile and who your partner is the first night so you have time to work this out). I suggest getting your hands on a cheap old copy of Microsoft Flight Sim and flying around doing approaches, steep turns, and climbing and descending turns in the 172 since all you really need to do is get your scan really sharp. The sim you use for the ride requires a fast scan since while you should be using small movements and corrections, the sim doesn't seem to register all of the small corrections so if your scan is fast you will notice it quickly and make sufficient correction before it is too late. I would guess that a very low percentage of interviewees here do a sim prep and I know it isn't necessary. Good luck.