Hi group,
I use history based parasolid design software at work and in the business we're in we need it. It goes somthing like this;

-Customer supplies 3d product.
-We incorperate the customer 3d model in the design life cycle.
-We design and model in whats called 'Top Down' modeling, where the customers model is at the top and everything designed and modeled is below that.
-Now, when the customer has a revision (design change) of their product we would substitute the old with new and our design which is going to manufacture this product would update within a few minutes and we are back on track again, this is the beauty of history based modeling.
-Thats if it was a small change, in the event the customer has reshaped the product dramatically by removing faces on the model and resurfacing this where history based modeling falls over all links and features used start falling off and have to be traced and rebuilt which takes alot of time, sometimes so bad that we inform the customer of additional charges.

That's one part of our business.

Then there is the individual model with the history tree, with simple models yes it's great but when you start modeling 'monster' models with 1823 features and complex shapes you can easily loose yourself if not careful and don't use proper modeling practice or else those error messages become a part of your career.
Then when I have do something quick or conceptual design I find it easier to blow parameters away and have no history.

I know sometimes in MoI I have to be careful in the way I design because it would be nice to go back and change the size of that fillet by just picking it and apply another value.
So my practice on more complex models is to Incrementally save, this is my history tree, have another session of MoI open and copy and paste part of the model that was ceated say 4 saves ago.

But when you consider MoI @ $195 a seat and the easy and quick work flow compared to the $15000 to $25000 a seat 3D giant that I use, I am as happy as a pig in poo!

Cheers
~Danny~