Personally the GXP looks the part of a sporier sedan much better IMHO. They're also making it simpler for things like the bumper, since all of the seperate lights are in fog light spots now. The Bonneville lineup looks much closer to eachother, since they changed it in 92.
Pontiac'* been on a "De-cladding" rampage since the aztec made it'* debut. It'* for the better IMO.