Good idea, but firstly the hitbox problem that has increased since the new running speed, should be fixed.
(white smoke when hiting the target directly but nothing happens, no damage nothing)
A nother problem is that this speed decrease the "Map-size" for infantry, because you can reach positions quicker logic or.

(it also increase action value and decreas tactic side, becasue of a lesser value of life)
The recovering from running is also in my opinion mutch to high, should take longer. That would increas the Map-size for infantry again. (when you out of breath you dont recover in 15 sec)
For coders with time:
when 80% breath then recover *2.0
when 50% breath then recover *0.5
when 1% breath then recover *0.1
(so when you run longer you need longer to recover)
Let us be honest, in PR we are 80% running and 20% walking.
In reality we are running 5% and walking 95% .
(this would increas usage of teamwork and transport APC, Helis etc.)
Different speeds for example MG, Rifleman and factions would be a cool feature.
But its not realy important or?