One star for performance, an extra star for customer service. I've also spent over an hour on Samsung technical support just now. As of today, I'm still getting an "error:Unknown error" repeatedly, and USUALLY the button to alert caregiver works (which isn't a useful feature for me as I don't get aura's). I have managed a "simulated seizure" exactly once while shaking it, then after you hit the button saying you're ok it takes me to a sort of "welcome" page I can't get out of w/o un/reinstall.