I imagine they're getting better, but a couple years ago had lots of customer complaints and experienced first hand a few instances that the vehicle would hit the brakes when passing a semi on the highway because it detected it as an obstacle even though they were in the right-hand lane (edit: just did a little googling, and there's still ongoing investigations of vehicles randomly braking with these systems)Cost? What is your life or that of your passengers worth? These systems work. Just saying...