Dfinch

This. The benefit of what Maltby does is it provides measurements you don't normally get from manufacturers. The final "MPF" number he gives is his own formula, which may or may not matter for an individual. You can argue that the formula benefits his designs, or that he designs to the formula (chicken/egg). In the end what matters is identifying the properties that matter the most to you and your game, and comparisons with past favorite designs helps with that. At that point you can ignore the final number and look at the specific measurements. The formula gives a very high weight to "C-dimension", which is how far away from the centerline of the hosel the horizontal sweetspot is. It also gives very high weight to how low the COG is. These factors benefit people who don't have the traditional "slightly heel side" and "shaft lean, compressed" impact that the best players tend to have. Those players will feel like they have trouble flighting the ball down or won't like the feel of a club with too low, too toe-ward sweetspot. If you hit more toward the toe, more toward the bottom, lack shaft lean at impact, like many many average players, those measurements will benefit you. The club will launch better and feel better because the sweetspot matches your impact pattern better than a "low MPF" club. I know from experience that if the club has a C-dimension of 1.2-1.3 and a VCOG of around .7-.75, I will like the club. This has been true going all the way back to the Macgregor 1025M blade, and I can look at irons I didn't like or didn't last long in my bag and those I consider my favorite sets and it is consistent.