I played for a few hours and I'm using Alternate 2, I reduced the sensitivity for the x and y axis two notches. Big difference.
The thing about multiplayer is that the game is pretty simplistic at first. It takes a while before you can earn the other classes.
The classes are what multiplayer excellent.
Rifleman:
Base class, no special abilities.
Engineer/Engineer Primary: Sets up an automated turret which targets the enemy.
Secondary: Repairs ammunition dispensers, mounted guns, and automated turrets.
Medic/Medic Primary: Revives downed team mates.
Secondary: Throws a health pack, which can be picked up by other players.
Scout/Scout Primary: Uses a cloaking suit to become near-invisible.
Secondary: Tags all on-screen enemy players with a hidden marker, which broadcasts their coordinates to team mates.
Assault/Assault Primary: Dons heavy armour twice as strong as normal.
Secondary: Temporarily boosts running speed.
Tactitian/Tactitian Primary: Throws a coloured smoke grenade, which serves as a spawn point.
Secondary: Requests air support from a sentry bot which targets the enemy.
Saboteur/Saboteur Primary: Assumes the disguise of a randomly selected enemy player.
Secondary: Throws a sticky, proximity-activated C-4 charge.
Eventually you'll reach a point where you can make custom classes. You can use any primary ability and mix it with any secondary ability.