What's your custom class setup? What gun do you use, modules, etc?
I use the Scar, wit stealth, armor, and mobility enhance.

All modules/secondarys/explosives are the same.

Secondary: Hammer (Extended mags)
Explosive: C4

Stealth Enhance III
Nano Recharge I (Need to get upgrades)
Mobility Enhance III
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1:
Primary: Scar (Reflex, Extended mags)
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2:
Primary: K-volt (Reflex, Extended mags)
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3:
Primary: X-43 MIKE
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4: This is a class I change regularly.
Primary: Scar (Laser sight, Extended mags)
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5:
Primary: Jackal (Reflex, Extended mags)
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I use this set up for 90% of my matche's

Primary - Scar - Granade launcher - Red dot site
Secondary - DSG -1 - Extended mag - Silencer

module 1 - Proxy Alarm
Module 2 - Visour Enhance
Module 3 - Loadout Pro

To counter Blindspot user's i replace Visour with Blindspot
If it's small map or were sniping is hard (i.e player's stay close proximate's and blindspot)
Also for 1-1's on small map's

Primary - Scar - Hologram - Red dot site
Secondary - Hammer - Extended mag

Module 1 - Proxy alarm
Module 2 - (cant remember top of my head make's your footstep's unheard)
Module 3 - Weopon pro

i dont see the point in using Stealth Enhance ect ect just use your scenery more and make sure you dont take so many risk's !

Right now im using this setup:

Nano Recharge III
Cloak Tracker III
Rapid Fire III

For guns, I use either of these depending on the amount of lag

Feline-iron sight, no attachments
Scar-iron sight, no attachments
F71 assault rifle, iron sight, no attachment.

But to be honest I think the perks are not balanced enough in this game. Just my opinion.

I'm using this right now. Just rebooted though, so all the stuff is at level 1 so far.

SCAR (Reflex Sight, Hologram, CELL Camo)
M12 Nova
M17 Frag Grenade
Proximity Alarm
Stealth Enhance
Aim Enhance

I have two main class sets I use:

Clan Game set:
Feline (Reflex Sight, Extended Mag)
Grendel (Assault Sight, Extended Mag)
Proximity Alarm
Visor Enhance
Load out Pro

Anything Else:
Scarab (Ironsight, Extended Mag)
Machine Pistol (Can't remember the name)
Nano Recharge
Tracker
Weapon Pro