zoomx:
nRF24L01+ should uses less power than ESP8266 using WiFi since it can be driven using the 3.3V Arduino rail (but a cap is useful!). I don't know if in ESP-NOW mode the ESP8266 uses less current than WiFi mode.
I have not considered that. I know the ESP8266 has a deep sleep mode but that is not practical for my immediate application.
The correct comparison is the combined consumption of the Attiny1634 plus nRF24 vs the ESP8266.
Prompted by your comment my initial measurements suggest the ESP8266 draws 80mA and my Attiny + nRF24 draws 30mA.
[paragraph deleted - added no value]
I will need to consider whether my little radio-control application can afford the extra current.
...R