It was a huge improvement and Ford needs to do this for the 2011's!
Maybe they did do something for the 2011s. I've had mine two weeks so far and yesterday we took it up to the northern part of the state up and down some steep grades on the interstate. I kept the cruise control on 70 going up a 6 mile steep grade. For anyone who has been to Arizona, this is on I-17 northbound. You go up about 3,000 feet in only 6 miles or so.
The engine got up to 3000 to 3500 RPM a couple of times and I did hear a louder hum from under the hood, but absolutely nothing out of the ordinary. This was by far the highest it has been pushed because all of my previous driving had been around town and I was taking it easy also for the first few hundred miles.
And the best thing about it going up hill with the hybrid transmission is no annoying downshifting all the time. My other car is a Jaguar and if I try to climb that same grade at 70 MPH it will constantly dowshift every quarter mile or so which gets annoying over 6 or 7 miles. The Fusion went up the hill as smooth as silk and the speed never varied off of 70. By far the smoothest, quietest car I've ever owned.