I think the word is mis used a lot. From what I see, "noob" is more of an insult, and "newb" is just saying they're new.

Noob as a word is a slang for Newbie. Newbie meaning new, and noob is a slang insult. Even so, people missuse the insult, such as "You rusher noob". When you tell somebody that they are a noob, you are insulting the little ammount of time they have played the game, which in most cases isnt even relevant to the situation.

My opinion= Noob is a missused word.