I'm not sure how the smart brake control enhances the smart city brake control - there doesn't seem to be much information on it. If anyone has more information on this added feature i'd be very interested.
I can say however, the radar cruise control works wonderfully. I've tested it a few times and love it each time I use it. The most recent time I was following my parents an hour down to DE and I set it to 75mph and medium-close distance following. The entire ride down it kept an even pace between them and I no matter if they were going 45 or 75. Even at the EZ pass you felt the car hit the brakes, slow down to about 25mph, then pick right back up again keeping the same even pace.
The auto high beams are ok, but can be really sensitive and sometimes go on/off a lot. There are times I like it and others I don't.
The lane departure warning some people find annoying but my wife and I actually like it. It's almost a game to not make it go off. I changed the settings to do a "rumble" sound rather then a beep so its not as annoying. The Rumble makes a low rumble strip like sound from either the right or left speaker depending on what side you drift on. At first we felt it was too sensitive, but we changed the settings to "Timing = At" and "warning = High" and found that it worked a lot better. We usually barely hear it go off unless we are legitimitly drifting. It is also smart enough to not go off if you have your blinker on while switching lanes.
Edit:
Forgot to mention the close proximity warning - it doesn't beep or make a noise which I think a lot of people were under the assumption it does (at least I haven't seen a setting for it to). When selected on the screen it just simply displays a picture of a car when one is in proximity. An arrow gets closer to the car as you get closer and then if you are too close it simply blinks the car icon. No noises or other notifications - you only see it if you have it active within the display.