[adrian_b]

IIRC the older Microsoft Basic for CP/M was significantly more powerful than ZX Basic.

This is not surprising because the Microsoft Basic was intended for computers with 8 inch floppy disks (the much larger predecessors of the 5 1/4 inch floppy disks familiar to IBM PC users), while ZX Basic had to run from a ROM with only cassette storage. Thus the former was expected to be used for bigger programs that could also process much more data.

The Microsoft Basic for CP/M was very similar to the later GW-BASIC for MS-DOS.

The advantages of Microsoft Basic that mattered for me at that time were less about any improved program control structures, but about more powerful data types, for instance double-precision 64-bit floating-point numbers.

[pjmlp]

It was, never used it, but it already suffices that it supported structured BASIC and a proper compiler.

Also to note, the original Darthmond BASIC was much more powerful than the ones on 8 bit micros due to hardware restrictions, exception to those that were good enough to run CP/M.