There were several reasons, my wife has had 3 Saturns before this one, we traded in an 04 VUE and Saturn gave us $2000 more than GMC would, the Saturn after matching option for option was $2000 less, that's a $4000 difference in Saturn's favor. Also my wife loves the tan leather, GMC had titanium, black and brick, yuk. I like the exterior of the Outlook more. The Acadia seemed to have less road noise, not by my much, but quieter and the seats were more comfy, but the Saturn won on pricing and looks. Also we wanted the red jewel, GMC only looked at was around in stock, which didn't get us what we wanted in options. When we went into Saturn, they looked, couldn't find one, so they ordered it, no issue.
Also didn't like the brushed aluminum in the Acadia, the faux wood looks so much better.