How is a banana better than an apple? :)
They are two different beasts, with two different stacks, and two different means of communication - all with completely different tradeoffs.<p>A Cortex-M0 + BLE setup would easily outlast an ESP8266 battery-wise, it would also make more sense on the go (BLE devices can communicate directly with a phone app, without much setup). While an ESP8266 is more general - can connect directly to wifi (more work, and more &quot;stationary&quot;).