I have seen quite a few posts across the forums complaining that scavenger doesn't restore equipment and the explosives such as c4 are underpowered in this game. Now, I understand why they are what they are. I recently drew the strong arm and danger close operation challenges. So, I set to work building a class for them.
Primary Weapon: Combat Knife
Lethal Equipment: C4 x 2
Perks: Danger Close, Strong Arm, Dead Silence, Reflex, Extra Lethal
I spent the last day just trolling free for all with this class trying to rack up the 500 or so explosive kills I need for the operations. C4 with danger close has nearly an 8 meter lethal radius against players without blast shield. The perk is kept in balance by it's high cost and the limits on the amount of explosives a player can put on a load out. Still it's loads of fun and most people don't see it coming.