Well, i've given up too. Everyone should just go grab a set of 20" dubs and slap em on there for the track since weight don't make a difference anymore apparently.
Thanks for your experience that adds no valid argument...I've read, and experienced the difference myself going to a 2 inch larger and 10 pound heavier wheel. The differences I've felt are in concurrence with this article here, and with many, many others I can assure you.
http://en.wikipedia.org/wiki/Unsprung_mass additional unsprung weight will affect braking performance negatively in our cars end of story, TT or NA, even with upgraded brakes. There is no valid argument that says otherwise. You can 'give up on me' if you want, I could care less....Good luck giving up on physics though, It will always win.
As little or as much money as it turns out to be, (redrill might be cheap, but the paintjob won't be, nor will be the fender flaring if done right,) at least it aint mine. They're still BMW wheels meant for the 5 series it came from, and still too big no matter how you spin it.