the Milgauss is just easier to wear on a daily basis.
Once you own both a sub and a Milgauss, the problem is resolved. this may however take a certain amount of time to acheive.
Best regards,
George

ruggedness, my take is Sub over Milgauss
accuracy, both are fantastic
long term value=Intrinsic
Hope you make one choice. No right, no wrong.
If you want to compare the Vintage, the funny thing is that the Sub was by far more popular than the Milgauss, which didn't sell well.
If you go to the modern playground, the Milgauss is not the first Rolex on which people would go, but compare a Green milgauss with a Sub, I don't know which one I would prefer... I would say the Green Milgauss, much funnier and crazier than the Sub, even the Kermit.
As for long term value, no opinion, here, as I don't have a crystal ball. I would just say that I'd go on the one I love the most.
Best,
Nicolas.