Changing oil at 50 hours excessive?

Just curious what everyone's thoughts are on when to change your oil? I heard PCM just put out a memo saying to change your oil at 30 hours now instead of 50. I've always heard to change it by 50 so my buddy and I thought we'd see how much truth was to this. He has a 2012 MB with a PCM(I'm pretty sure) and I have a 2006 Sanger with the black scorpion. We both run about 3000 lbs ballast in our boats. He sent in a sample from his last oil change after 50 hours and the results came back totally fine. They said try 75 hours next time. I sent mine in with 60 hours on the oil and they told me try 80 next time because the oil was still looking great. We both were using Delo 15-40 oil.

Now will I wait until 80 hours to change my oil....probably not, but it's good to know I don't need to be worried about going over the 50 hour mark if I am close, and have a long camping trip coming up.