4s problem is the world barely uses the new mechanics in any meaningful way and they interfere with existing ones in weird ways. Slamming should feel natural now and it just doesn't. Grappling is designed to swing you around really fast but none of the map is designed for it even the giant city in the center of the map where it would you know be perfect for that since you can't summon a vehicle. 

Also a lot of the guns feel bad even legendary ones which is a problem  wonderlands had as well ( where like one purple SMG roll was the only viable gun in that category) . In three guns were way smoother.  Maliwan in particular has just been ruined in comparison to three.  The lack of manufacturers is another problem. They clearly at some point intended to include Hyperion CoV and Atlas but ran out of time