I agree with OP. Kevlar needs a desperate rework, it is not competitive in its current state. On EU most players use CA3 and occasionally fragile.
This would be a balanced yet effective version of a "Kevlar 4" I believe. Compare this to the stats of "Kevlar 3", where the disadvantages outweigh the benefits.
(P.S. sorry for widescreen shot i play in 4:3)
+45% Player health
-20% Reduces crouch speed
+20% Time to climb ladders
+20% Time to kick doors open
Let me know your thoughts on this