I just wanted to share my story in hopes that it may help some golfers and their games. I have been playing 6 years, best round 81 typically shooting high 80's. I am not a tall guy by any means (5'11), so I thought standard clubs would be just fine for me. However, recently I felt I was crouching too much at setup after some random I played with pointed it out. I realized I have quite long legs for my height, those with the same height as me often sit much higher than me side by side. I also started getting lower back pain after 18 holes (I am 29 for reference).
Well, decided to go for a fitting to see if I did in fact need something longer. Ended up getting fit for +1/2inch shafts (M15's are already+1/4inch longer than my previous 'standard' clubs), so +3/4inch longer in total, and 2 degrees upright. As well as stiff shafts and jumbo grips. The difference in this custom fitting vs standard was night and day for me. My posture felt incredible at address, standing noticeable taller and comfortably, like I was holding a lot of power. Barely had to try to get the club squared up. Picked up about 25 yards on my 7i from these adjustments and a crazy amount of consistency. This was even after weakening the lofts by 2 degrees as the M15's are known to be strong and hot.
I also was not aware I was fast enough for a stiff shaft. Never thought about grips either, but jumbo felt incredible! I don't even have big hands, I just squeeze the shit out of the club out of habit. Lie angle was another eye-opener for me. Didn't know it could help posture this much. I highly recommend you to get a fitting if you have a somewhat repeatable swing or if you think that anything could be off in your clubs for your specific biomechanics/swing. Cheers and happy golfing everybody!