The original and best reviewed is Ember and Ember 2. It retails for NZ$249 which is ok conversion at today's exchange rate when compared to current amazon prices.
https://www.jbhifi.co.nz/products/ember-temperature-control-smart-mug-2-295ml-copper $249
https://www.jbhifi.co.nz/products/ember-temperature-control-smart-mug-2-295ml-black $197
I'm finding it very very hard to press the buy button on a $250 coffee mug especially in NZ summer. It will be really nice in winter. That is when I started thinking about it. I was too slow drinking my morning coffee today ; )
My question is do you have one of these and what other brands or methods did you try etc?
Edit: Added plain black version E2 for $197