As a five month owner of a manual tranny 2004 HCH, I can assure you that on a FLAT or LIMITED GRADE road, the cruise on the HCH does a PERFECT JOB of maxxing out MPG. And in addition, the computer control is far more excellent at maintaining a steady pressure than a human foot could possibly be.
I use the cruise all the time and turn it off only when I have an incline that will cause it to accel in ways I don't want it to (in other words, when I see that the real-time MPG meter is dropping.)
So to each their own methods, but for me, when the real-time meter is hovering around 80-120 when I have been cruising on a flat road at 40 miles per hour for a mile or so, I could not possibly do better with my foot.
I'm not a good authority on hilly terrain in this car, because I have not really experienced that on a daily basis. But for flat roads, I would consider myself an expert. :ph34r: