I was coming from 10 years of driving manuals, as well as VW DSG gearboxes in the wife's car, and I am completely thrilled with the 8AT performance.
It's unbelievably smooth, it shifts faster than anyone with a clutch can (I don't know why everyone is stuck up on the DCT vs AT argument in this thread, the real answer is the 8AT is faster than a manual).
I drove a lot of cars before giving up my clutch, and theres times when I still miss throwing a good heel toe onto an off ramp, but other than that the smoothness, directness and speed of the 8AT is better than any other automatic I've ever driven.
Current: '15 M235i Vert
Previous: '13 335i, '08 TL-S, '00 Corvette