It would have been so different. Not as much suit porn to begin with and Arthur's characterisation in fic would have been more geeky/nerdy/hipster/nice guy than badass/Vulcan/what-are-feelings-and-relationships?

Arthur/Ariadne would be hipsters in love and probably less popular because of their similarities = less conflict and contrast.

Arthur/Eames would have seen even more bottom!Arthur and age difference fics.

I'm glad JGL took Arthur in a different direction because the tech support guy in movies and TV shows is always geek chic - Converse and casual t-shirts - that it's a bit of a cliché in costume design.