I am definitely a happy duplicator when it comes to such basics. I think Angie has said the same thing. I have been super glad in the past with most of my duplications. A few mistakes but in general many more successes, and the happiness of those outweighs the mistakes by a long shot.
A perfect pair of pants is rare. I say duplicate and enjoy them. It's not like they are $500, so I think the risk is low. Plus as others have mentioned, Athleta has a good return policy. There is no risk in buying but holding off wearing for a week or so if you want to be sure.
I have found two tops I'm quite happy with recently, and will definitely be duplicating in other colors.