Okay, so I can't compare her to Gus or Lens since I haven't recruited either of them yet but since I recently got her on my second playthrough, I thought I could share my thought on her. Personally, I think she is an okay merc but she is clearly designed to be played in a specific way.
What make her unique: Her Heavy Duty talent make her keep her free move despite being equiped with heavy armours and cumbersome weapons, that combined with her Fast Runner perk mean she's propably the closest a merc can get to a mobile tank.
What she's good at: As she have the Heavy Weapon trait, she can use those effectively. She is also an excellent shock trooper when using a shotgun thank to her good free move and her Breach and Clear perk.
What she can do but isn't her speciality: Ironically, despite being listed as an explosive expert, Fauda isn't all that great at explosive, she can still use the less complicated one like Grenades effectively though, especially when taking advantage of her Breach and Clear perk. She also has very decent Leadership so she will be a good help with training Militia but this should never be your main reason for picking her as Lens is obviously better than her on this point.
What she can't do effectively: Because of her decent but not great Marksmanship and of her low Dexterity, Fauda will never be a great sharpshooter. I also suspect she wouldn't be the most effective user for Assault Rifles.
What could have made her even better: Two perks which would have really helped Fauda stand out even more as a shock trooper would have been Vanguard and Shock Assault. Having slightly better Health and Agility stats would also help in that regard.
Important point: Despite not having the trait Psycho, it is required to have her kill ennemy to be happy. Otherwise, she will ask for more money to stay at your service.
So in a nutshell, Fauda is pretty good at close range, at dealing damage to groups of ennemy and with heavy weapons, all that while staying very mobile. She certainly has a fun playstyle but if you're looking for a explosive specialist, a leader or a sharpshooter, they are better option than her at a lower price.