I haven't stepped outside the parametric world since the mid 90's. Like Sabastian stated there is more to it than just the dynamic relationship between two features on two different parts. When you couple that with Parametric data management it gets even more powerful. You can control changes/revisioins of entire designs that can be retrieved at any time Say you designed a product 3 years ago and it has been in production for the past 2 years. You can retrieve the state of the design with the parts as saved 1 year ago and compare it to what it's current state is. You can also route products through workflows that require approvals by other individuals before moving past certain states. For example... you design something and want a prototype that cost 1K. You would bump it to an approval state where your boss would have to sign off. He gets an email notification telling him he has an action item. He goes in and approves it. Once he approves it gets forwarded to purchasing to cut a purchase order. I just set up our system at work 2 years ago but have been using this type of technology for a long time.

This is a demo of the system I set up at work and gives you and idea of the whole approach.
https://www.youtube.com/watch?v=1aySYterKog