Works well, looks cool, software seems stable. Wish it had longer battery life off the charger (less than 2 hours when set at the highest temp) and held more volume. 4 stars if it did either of these things better, 5 stars if both. Got it as a gift for my other half. He likes it as he works from home and cup can sit on charger for most of the day. Cool gift but wouldn't want him to know how much I paid for it...