It is still early days but seems to work well. It feels sturdy and is shiny and clean. The buttons are a little finnicky to use but operation was easy to learn. My first test was to fill with hot water (the LCD said 82 Celcius) and I had a preset of 55 Celcius. It slowly cooled down to 55 and then proceeded to heat. Battery was still at half charge 12 hours later. In practice the tea would have been drunk well before then! It is a little heavy, and just holds 300 ml, but seems to work exactly as expected and we should get lots of good use out of it.Now that I finally figured out the directions which are thankfully on a sticker on the mug in both Chinese and a rather strange English, I love the heated mug and use it everyday, charging it overnight. I hope the rechargeable batteries will last for some time as they seem permanently attached to the mug. It seems to be not spilling in my backpack and the battery lasts all day. The 10oz size is the perfect size for me to last for many hours of drinking. It is much better than the Cauldryn mug that I tried out and returned because the battery only lasted 3 hrs and it had an enormous transformer on the charging cord. I'll be keeping this and continuing to use it everydayPros: This Futurelabs mug battery lasts all day and is charged by USB-C, I keep it at 150F all day, it doesnt leak. Cons: the control buttons are sometimes unresponsiveUpdate 6/21/2022 Battery dying, Battery is hardly holding a charge even though I charge it overnightGreat product! Way better the Ember! I’ve had it for 3 weeks now and it works amazingly! I didn’t have to charge it until day 6. As long as you clean every night and don’t overfill, it works like a charm!The products overall is as described in the listing I am quite happy with its operation it does hold a charge for a good while and will keep your coffee piping hot for hoursReceived as a gift and the translated instructions are terribly difficult to understand. Trying to just figure it out myself. I think I have them set but really can't be sure. I will update the review if I can figure it out. Very expensive for such bad instructions. I would recommend caution.Battery dies instantly and my cup took hours to get changed or even didn’t changes battery. I had to repeatedly unplug and plug again and come back after minutes to make sure it’s charging. Anything than that it’s comfortable .The only problem is that the temperature setting are in Celsius