Pro Perks

My usual set up of Pro-Perks included Scavenger Pro, Marathon Pro and Steady Aim Pro. I've tried a few variations and there are a few that I sometimes think would help me more but these are the ones I keep coming back to time after time and here are the reasons why.

1: Steady Aim Pro

Overview

Steady Aim reduces the size of the hip fire crosshairs to 65% of their original size. Its pro version reduces the fire delay after sprinting and the knife lunge recovery time to 60% of their original values. Note that the actual knife lunge animation is not shortened; Steady Aim Pro simply decreases the time it takes for the user to put the knife away after a lunge.

Pro Challenges

Quick Melee – Melee two enemies consecutively within 5 seconds.
Sprint Kills – Get 100 kills after sprinting.
Hip Fire Kills – Get 150 hip fire kills using Steady Aim.

I use steady aim for the simple reason that when I run into another player by the time they have brought their gun up to aim and shoot I've already killed them as I have fired directly from the hip i would guess that around 80% of my kills from my primary weapon come from the hip. This is a massive reason why i have a very good Kill Death Ratio at 2.50

2: Marathon Pro

Overview

Marathon doubles the player's sprint duration. Its Pro version gives the player unlimited sprint duration.

Pro Challenges

26 Miles: Sprint 26 Miles using Marathon.
First Blood: Get the First Blood Medal 10 times.
Captures: In Capture the Flag, get the Flag Capture medal 15 times while using Marathon

I use Marathon Pro as I'm a big fan of Light Machineguns, The only drawback to them is they slow you down almost to a snail's pace. Marathon Pro just helps ease the pain of this drawback.

3: Scavenger Pro

Overview

Scavenger allows the player to see and pick up ammo bags left by dead players. These bags replenish one magazine of ammunition for each weapon the player carries and one lethal grenade. Its pro version allows the player to pick up one tactical grenade with each bag and spawns the player with maximum ammo.
Notably, Scavenger no longer replenishes weapon attachments, launchers, or equipment. However, Scavenger Pro does give each launcher an extra projectile.
Scavenger gives the player model a backpack and ammo pouches.

Pro Challenges

Resupplies — Resupply 150 times while using Scavenger.
Grenade Kills — Get 5 Lethal Grenade kills with a resupplied grenade.
Kill Count — Get 5 kills without dying 5 times.

I use Scavenger as I hate running out of ammo especially when you're on a large kill streak. The last thing I want to do is look for a new gun and end up with a shotgun or something equally pointless. Another great advantage is unlimited grenade refills.