I agree wholeheartedly that a large-scale edit with a vet can be traumatic but rewarding.
Working with Editor Ed on The Spell Keeper was a huge education. I thought the manuscript was pretty good before the editing process, but man, did we tear it apart! I actually dreaded his emails at one point. (The end result was still pretty "intermediate" compared to what I'm writing now, but it was a huge improvement over the original.)
You will instinctively take a lot of what you learned to the next project. When working on Veil of Whispers and Shadow Summit, I noticed many of my previous bad habits were diminished.
(Many still linger, of course...)