I have only used SCC a handful of times in 4 years, to be honest. The only times I've found it useful were those rare times I'm stuck in slow-moving traffic, like when people are rubbernecking an accident.
Other than that, I don't much care for it. People here will quickly jump in between you and the car ahead if there's enough space; this of course makes the system freak out and brake hard. And that's definitely not good when you have someone riding your bumper at 70, who's very likely not paying attention.