I have no idea what the F is wrong with the sprint. I mean you wait 1 second to see the model moving faster, while other games has sprint instantly.
In DirtyBomb when you hold SHIFT, first you’ll walk like normal and after that ONE SECOND you’ll start running. This mechanism annoys me and makes sprint useless in several scenarios which leaves me often to death…
Glad DB is not having that, which is positive 

