1) 11C 2) Jag 3) Trac5S 4) Trac5 5) T5 I don't have the Lynx or Cougar, but I'm sure they are gaining popularity.
1st place is shared between TRAC 5 and T5 AMC. TRAC 5 is the most powerful one, while I have the fondest memories of using T5 AMC. Cougar is OK, but has too much horizontal recoil IMO. Jaguar is a very good and versatile weapon, but I wouldn't call it my favorite. Hated the old Lynx and didn't acquire a taste for the new one, but it's OK as a weapon, definitely has its place, even though it's inferior to the higher damage tier weapons (not GD-7F / Serpent in particular, any weapon of a higher tier). TRAC 5S I auraxiumed and shelved long before I began doing deep analysis of weapons, so I kinda don't have an opinion about it stats-wise.
I have an extremely hard time deciding between T5, Trac 5, and the Jaguar. Each one, I've used alot and love. If I have to choose it will be: Trac 5 (for sentimental reasons mostly I guess) Jaguar T5
Well, I've only really used three. My preferences would probably be different if I had spent time playing with other carbines. 1. T5 AMC (the old sound was better ) 2. Cougar 3. Trac-5 I tend to prefer the consistent mid-long range carbines with other factions as well. Razer for NC, Pulsar C for VS (Pulsar is a beast, I love it). With all of these, I use a compensator, foregrip and scope (3.4x chevron for TR and VS, 4x crosshair for NC).