Hmm true, I should absolutely try and make braking an independent stat instead of just derived from weight.
Low booster gameplay definitely feels more weighty (if that makes sense) with having to turn in wide circles instead of being able to move omnidirectionally seamlessly. Making boosters something you always have to use, else you get punished, has always been my pet peeve about games like AC.
Funny you mention MechWarrior because the walking/running scheme is basically a MechWarrior-style Legs > Torso system but automated to work with "arcade" controls. I actually implemented it as a test when I saw MW5 had a new FPS control mode and it was janky as heck and thought I could do one better. You could say it was heavily inspired by the Scorpion tank controls from Halo.
I actually tried implementing it to work with booster movement and it looks surprisingly natural.
As an aside, it's close to how I hope AC6 handles the unlocked combat with free camera and movement. Excited for the gameplay preview later!