E60 M5 vs Audi S6 (not a race)

Hey guys... Currently an E39 540i owner, but had previously owned a string of Audi's.
Looks like this spring/summer I will be upgrading though to either an E60 M5, or a 2007 Audi S6. Obviously the M5 is faster... A lot faster. However, to my personal taste, the S6 is more elegant, inside and out. I have read the horrible reviews of iDrive, and a clunky/jerky smg transmission, but also the glowing praise of the suspension and engine while in "M mode". I am aware that these are two very different cars, and performance wise, the S6 is probably much closer to the E60 535xi with a tune, however these two V10 wielding chariots are the main candidates I am considering.
My question is, have any of you faced the same decision? What were your deciding factors? Is iDrive THAT bad? Do you get used to the smg jerkiness?
Thanks in advance for any opinions and advice you may have.

Jordon

I think my 06 M5 is the pinnacle of automobile engineering.Combining luxury and power.The car is built for safety first.I like the SMGIII trans that teaches you how to drive 500 hp safely,I have had no problems with the trans or the idrive computer. Complaints- turn signals prone to staying on. Paddle shifters are overkill crowds the steering wheel .