In the for what it's worth department - and I know you've already helped by getting different bushings - I have to ask a question.
Was the car you came from a CVT or conventional transmission?
When our CVT first came out several years ago, some of my customers noted they felt a bit of motion sickness. The Continuously Variable changing of the transmission was too subtle for the customer to consciously feel or hear, but they had a sensitive inner ear and could feel it, causing motion sickness that they wouldn't feel, even when on a small boat on a lake.
Combine the CVT with the new, more floating suspension on the Ascent, and we're in a perfect storm for motion sickness again, especially with those people who aren't used to it already.