As stated in the topic, i think you deactivated the inertia since a while (since 0.63 already?)

Basically people can run around like weightless squirrels on an overdose of coffee and do almost 180 degree turns on full speed.
Also if you are standing still and starting to sprint you are from speed 0 to max speed instantly. Instead you should start a bit slower and go full speed after a few meters only.

This is actually a big gamebreaker, because you can often see people zig-zagging around in open fields, evading bullets or people in close quarters, melee just run 360 around you constantly as there is no inertia or weight at all.

Optional, suggestion: it would be cool if people with heavy gear can not sprint the same speed as a due just with shorts and a t-shirt. Also not for a short while for the same speed.