As a new user of TACC, I must say that I'm not impressed. It may be OK for light traffic on a highway, but for heavier Bay Area freeway driving or on city streets, it will, at the least, take some getting used to. Here's why: 1. I'm used to backing off the throttle or starting to brake when I can see traffic ahead beginning to slow down in my lane. TACC appears to only look at the car directly in front. So, where I might begin to slow down TACC sometimes continues to accelerate and then brakes way later than is comfortable (or energy efficient). It shouldn't just track the car in front. It needs to be smarter (easier said than done). 2. In moderate to severe braking, I always look in the rear view mirror to adjust braking rate and closing distance to avoid being rear-ended. TACC seems to be totally unaware of the vehicle behind. 3. In stop and go driving, it's a little late starting up from a stop. Drivers around here are not patient with slow-starters. 4. When setting a comfortable following distance, the stopped-at-an-intersection distance to the car in front is too long. These two settings should be decoupled. 5. TACC (Traffic Aware Cruise Control) seems like a misnomer. Maybe its an aspirational term. What it appears to be is REACC (Rear-End Avoiding Cruise Control). Otherwise, it is kind of cool. If I weren't an engineer, I might even call it a little magical.