Here's my Constructive Crit:
The black bars in between the different class buttons seem a a bit too thick
Also, I don't think it should have the Faction name next to the class in this menu, seeing as how your faction is picked manually, previous to picking a class.
Possibly different names for the different classes for each faction? i.e assualt for NATO would be Rifleman or Soldier, and for MELA it'de be Militant or some shit.
The previous suggestion is just that, doesn't seem too helpful but i'm just putting it up here incase it sparks any other dieas.
You could aslo add a custom Gmod skin that makes the area around the menu look like bullet hole'd metal or something, for added effect/immersion.
Loadouts would be pretty neat to have too, you could just add it underneath or above the little class picture thing.
Also movement speed and stuff, just general stats that are modified by classes should be added.
Some classes should have weight limits aswell, so you can't have scouts picking up LMG's and being just as effective with it. Obviously some one could just spawn as sniper, drop their gun or suicide, let an officer pick it up, and then respawn, and go out raping.