I wanted to see how well it works.
I was stopped at a steep hill and the traffic light went green, I took my foot from the brake and the car stayed put. No backwards roll. However, it didn't last that long, maybe 2 seconds before I felt the brakes release and the car starting to go in reverse.
I'm thinking it might have been wiser not to use a timer on the hill start but instead sense when the gas was being pushed hard enough to get the car rolling forward before releasing the brakes
All in all, I think it's a positive feature. Some more testing is needed though.