This year is definitely different than M25 in regards to the Min Player Speed Threshold slider.
Last year, at 0 threshold O-linemen were too slow when pulling to block and your RB often bumped into the back of them or out ran them.
This year, 0 threshold is the way to go. That problem with O-linemen being too slow is gone now from my experience running the ball so far.
Also, it wasn't until I used 0 threshold did I see players with elite speed and quickness, such as Tavon Austin (96 spd, 97 acc), Brandin Cooks (95 spd, 96 acc), and Devin Hester (97 spd, 94 acc) for example, get proper separation from slower players. I tried 35 and 25 threshold and basically nothing changed, and they also didn't get the separation you'd expect from elite speed players.
I used 25 threshold in M25, and that worked fine, but this year something changed with threshold, and 0 is the way to go. Especially now that your O-linemen are quick enough to pull and block on running plays with it at 0.
I play on Normal speed, by the way, but it works just as well on Slow speed (see Armor and Sword's sliders).