Yeah, the block editor is a quick win for younger children, but it's not good for teaching more realistic approaches to 'proper' coding; heading the Java or MicroPython route seems to be more suitable and engaging for older pupils.

The guys who ported MicroPython to the micro:bit have done a great job but, regrettably, by the time the MicroPython framework has been loaded on the micro:bit, the amount of room left for more complex programs is a bit tight.

Arduino is used in UK schools, but the one I hear a lot about is Crumble as it's designed to build motorised things very easily: http://redfernelectronics.co.uk/crumble/

(Disclaimer: I am a volunteer STEM Ambassador working with UK schools and educators in the fields of electronics and computing. I have no business relationship with Crumble)