It is quite obvious from the activity on the Siemens PLM hosted Solid Edge newsgroup that users have downloaded or been shipped their copy of Solid Edge with Synchronous Technology (from now on referred to as "ST"). It is also obvious that existing users of history based modelers must "unlearn" what has been ingrained in them over the years when they start using ST.
What they must "unlearn" is this: There is no magic time machine that will let you go back in history and erase something you did in your past.
Sounds like science fiction doesn't it?
No doubt you've seen the movies where some character goes back in time, steps on some bug, and then returns to the present and finds out they have changed the entire history of human evolution. Then they spend the rest of the movie trying to fix what they unintendedly did. Sound familiar?
This is exactly what we have been doing for the past 20 years in history based modelers... going back in time before the feature we want to remove existed, and erasing it. We then go back to the present to see what our change to history has done (sometimes expected, but often unexpected and we spend the next few hours fixing what we unintendedly did).
ST brings us out of the science fiction and puts us back into reality. To delete a feature, you stay in the present and delete the faces that make up the feature, or you fill in over it. The remaining faces adjacent to the deleted feature fill in to heal the solid or the embedded faces disappear. But nothing unexpected!
Definitely more straight forward and understandable, but for those who have been using the magic time machine, it is a foreign concept. ST is here, it's time to return to reality!