I recently test drove both 2008 and 2009 335xi/xdrive coupe manual with Sports Package. The 2009 felt way more planted and not as wobbly as the 2008. High speed in tight corners with the 2009 felt very well planted and no body roll at all. The 2008 had a little more body roll.
So, maybe the OP has a point of a possible difference between the two.
After the test drive I am leaning more and more towards a 2009/2010 coupè 6MT ZSP with the new iDrive.
A picture of 3 cars beside each other would be nice.
(1) 2008 335xi w/ZSP 18"
(2) 2009 335i xDrive w/ZSP 18"
(3) 2009 335i w/ZSP 18"