s2
I do not have the complete S2 package, but I can tell you that the stage 2 suspension is worth it and a big improvement. It has a smoother ride along with a more planted and solid feel. I have the stock OEM 18's on the car and I agree with you on the price of the Dinan 19's if you do not like the look of them, I would certainly look else where. I have not taken it back to the track yet to get a sense of how big the difference is under extreme conditions, but the everyday driving experience is certainly improved. Bimmer has an article on the S2, and Car and Driver is comming out with one in the next month or so.
I plan to do the S2 engine mods in the spring and will let you know what I think, if you have not already pulled the trigger by then.
My mods so far are the Stage 2 suspension, strut braces, drilled rotors and a supersprint exhaust. I am planning on the UUC rasp pipe this winter and then the Dinan engine mods after that.
Good luck and have fun