I can't help thinking you got more advise than you bargained for here. I also find the comments about how the Bose sucks but get it anyway rather interesting. Kind of a "I hate mine but you can't live without it" thing. For me my Cab already had it, the Boxster I had previously did not. For my needs the standard system was fine. If I were optioning the car I would leave it out either to keep the price where I wanted it or to make room for something I wanted more as I could easily live without it. But, I drive a convertible and I might have a different opinion if I were driving a coupe where the sound benefits of so a called "tuned" system would be more evident.
Whatever you do don't leave it off if you "really want it" as the total cost difference for adding it is insignificant when you're already looking at $ 105,000 for your car and your disappointment from not having it will bother you as long as own the car. The added cost of the option will go away the moment you take delivery. Whatever you do, have fun with your new car.

 

I had my C2s for 5 1/2 months with the Bose system. It is well worth the price.
Last month I traded it in for a 2011 GT3 with the sound plus. Strictly speaking on the sound, there is no comparison between the two. Now I listen to my engine instead of the great sound of months ago.
IMO either order it, or never listen to it if you choose not to.
Best of luck!