I don't think it can be both un-noticed after awhile and 'a nice detail in the back of your mind' - particularly since many users will not find it a 'nice' deta

I don't think it can be both un-noticed after awhile and 'a nice detail in the back of your mind' - particularly since many users will not find it a 'nice' detail from the start. It might become a niggling detail, and that's not good. Also, I've never felt 'bored' from seeing a native dialog box, and I've never thought of a paper clip on lined paper as a thing of beauty. Neutrality for these kinds of quick-and-functional interfaces is probably the better UI design decision.