Yeah, I think the weight is inconsequential. I don't think that Shimano or anyone else would cite the weight as a meaningful difference between Tiagra and Ultegra - but they would point to the forged hub shell, internal grease sleeve, and the super polished bearing races. And I wonder if these matter at all. Is it just largely needless features that get people to think they're buying a much more better product than the actual difference? The list price diff is $30 compared to $90, which is quite a bit.