Just an update:
I picked up the car today and I love it! The seats are superb, and other than the extra thigh extensions, I didn't find the extra controls too useful. The comfort of the standard seat is still excellent compared to my e92 with sport seats. The funny thing is that the bolsters on the e92 had a wider range of adjustability than those of the F13s comfort seats. All in all, I don't feel like I missed out.
2010 335i (E92) - ///M Sport (225M) - Alpine White - Black Leather - iDrive - Comfort Access - Logic 7 - Cold Weather - iPod/USB - Steptronic
2008 528i - Alpine White - Cream Beige - Light Poplar - Premium - Cold Weather - iPod/USB - Steptronic - Navigation