I bought etwow GT 2019 model without the drum brake. I usually don't speed much, less than 30 kmh and it happens to be my old model booster plus' maximum speed. By the way the GT's maximum is 40. Personally 30 is more than enough in the city commute and electric brake is good enough if you don't speed more than that. When I tested up to 40kmh it was a little scary. This GT model is so much powerful and runs longer. I was happy with my previous booster plus model that I rode past 3 years so it was an easy decision to buy etwow again. And I didn't need bluetooth function or drum brake with $200 more. Any cables and wires involved, I'm mechanically challenged, so without works better for me. This GT model is a huge A+. And etwow was very kind through their email communication.