I find it pretty stupid that people think Luffy will also affect the environment with his awakening. Doffy's Ito Ito is already concerned with external factors like controlling others or cutting things far away from Doffy. He can use it internally but not in a way in which it can apply its DF powers to himself. Same applies to Robin, she could probably change an entire area to arms just becuse it would fit the theme of her ability and her DF always working externally.
In Luffy's case his DF pretty much only affects himself. He's rubber and can manipulate himself, he can control the internal blood flow, etc. His DF does not affect anything externally (directly). Thus his awakening would obviously be something which is only concerned with awakening his own rubber characteristics. I'm going to guess he will become like Mr Fantastic from the Fantastic Four and gets the ability to manipulate ever cell of his body completely, but that's just my wild guess. It's not strong alone though, the user himself needs a high level CoO and Haki to make it what it could be. I'm going to guess Robin's will be the strongest since Brook will most likely be reviving fodders.