The beta was bad.
- weapons weren't balanced (shotgun and hammers dominate, DMR does nothing)
- hit accuracy wasn't there (headshots only registered on the forehead, not face)
- severe player slowness

Some of this seems to be fixed in the Campaign / FireFight mode. Again, can't say what's up with MatchMaking yet.
+ player movement speed is up. Jumping is still very grounded when compared to H3. Trying to jump up stairs to get up them faster no longer works.
+ DMR has some good "pop" to it.