Nadia, being the final companion that Jedi Consulars get, hasn't seemed to have gotten the attention that other female companions have. When I first talked about her, just after beta, I described her as an annoying school girl. As it turns out, her personality isn't exactly the same in the game as it was in the beta version. Bioware reduced the amount of complaining she does and she seems to be a lot more effective as a DPS companion. With the 30% armor buff Nadia gets in Game Update 1.2 tonight, it will make her an exceptional companion. Not only does she put out substantial DPS and AOE damage but she also uses the same gear as you. This makes it really easy to equip high end operations and PvP gear for her. Giving Nadia all my hand-me-downs gives her a huge advantage over my other DPS companions. She is a loyal companion and will also provide you with a streamlined story arc. I was able to complete Nadia's story line faster than any other companion's. If you are playing a nice light side Jedi, she will love almost all of your decisions. Most conversations awarded 100 affection from Nadia.
Nadia has 8 unique looks available ingame at this time; one default and seven customizations. The first time I saw Nadia in beta she actually had customization 3 as the default look. Bioware later changed it to the one she has now. Regardless of what hairstyle or skin color you choose for her, she'll always come default with a painted face, giving her a very Queen Amidala look.
The downside of the customizations for Nadia are the price of them. They each cost 35 000 credits. The first six are all available from the one unique vendor, Sergeant Koam. He is located in the Republic base on Ilum.
The security key vendor Captain Kneely on the Ilum space station is where you'll find the seventh customization. The cost is also 35 000 credits.
I personally chose customization 3 and considering most available outfits do actually cover her body (unlike the bikini) face painted marking and hair color are the extent of her variances. Even with a uniquely painted face, when you close up and personal with her you will notice that each customization includes a different facial shape.
Don't forget to check out similar posts:
Our full list of companions and gifts
The Many Looks of Elara Dorne
The Many Looks of Kira Carsen
The Many Looks of Vette
The Many Looks of Mako
The Many Looks of Risha
The Many Looks of Nadia Grell
For information on customization options for other companions check out the other 'Many Looks of ... ' posts on SWTORFace.