Golfers buy clubs based on TV and magazine ads or by noting equipment the world's best golfers play. Over the last several years, for example, Taylor Made has produced the following drivers: R5, R7, R9, R11, R1, R15, SLDR, M1,and M2, along with various Burner and Rocketbalz models. Based on the advertising you've all seen, each successive model should give you about "13-17 yards more distance."
Let’s think about this. If that were the case, you could hit the latest model more than 100 yards longer than the R5! I have measured most of these models on my Flight Scope launch monitor---extraordinarily accurate and considered to be one of the two best available. Guess what? These are all good drivers, and yes, there have been some improvements, but nowhere near the magnitude of what marketing would suggest: the R5 measures just about as well (within 15 yards) as the latest and greatest.
This should not be a surprise----the restrictions placed by the USGA on how hot a driver head can be have not changed in the last several years. While the clubs have not gotten much hotter, the marketing has! Major companies have stockholders who want to see increased profits. To do this, they regularly introduce new models to lure you into purchasing the latest and greatest. Please watch the following instructive video (“Facts of Life about the Golf Industry) by Tom Wishon, technical advisor to the PGA and the most prolific club designer ever.
After you’ve watched this video, you know the best thing you can do to improve your game is to get a real fitting by a certified clubfitting professional. This will enable you to play to the best of your ability. Demo days, fitting carts, and golf superstore "fittings" do not constitute a real, professional fitting! Here is another informative Wishon video.
Check the various links on Fitting to see why fitting is so important and what it can do for your golf game.