I don't have Campy so I can't comment on that brand. But there have been improvements in shifters and derailers in the Shimano line-up. IMHO, this benefits the mid level models the most. As an example, the DA front dr shifters had a half shift adjustment added many years ago. That has worked its way down first to Ultegra and now to 105. Derailer actions, especially rear, have been improved over the years, but it's not a huge improvement so it is not noticed. MTB shifters have improved quite a bit over the trigger shifters that were available in the early to mid 90s. Some of the entry level stuff available today is quite good.