You know I had a similar thought after I got my 06 Coupe and then found out all the cool stuff on the 08...I debated about getting an 08 or modding my 06.
Modding the 06 won out...simply because there were a certain number of mods I was going to do no matter which one I had. With that in mind the 08 would have been more costly and after the mods advantages of the 08 became less and less.
Besides for the extra coin it just wasn't visually different enough for me to feel like I just spent more money on a new car. When I sit in it in the garage it would just feel like I spent more money for what looks and feels just like my last car...and that would be silly
And as the others have said...your car would destroy a stock 08 in a race!