Could it be that you have to drive a 987 more extensively than a typical "test drive" to detect the differences?
I test drove a few 987's when I was looking for my Boxster and didn't notice much difference - thus, the 986 purchase. Seemed to me that the notable difference was between the S and non-S models rather than 986 vs 987. Reading your review now makes me think that maybe I missed something during my short test drives.
