Retrocomputing enthusiasts keep debates like this alive even today.

With single-byte addressing, I'd say even a 1 MHz 6502 can make a 4 MHz Z-80 sweat. ;-)

And, for the MSX crowd, having to do 3 OUT's, one IN and an OR just to set a pixel is definitely ludicrous.

For pure computation a Spectrum can match a C=64, but as soon as any of the Commodore's hardware assist kicks in, game over for the Speccy.

And the QL-inspired Spectrum+ and 128 remain some of the most beautiful 8-bit computers ever built. I love that keyboard.

Commodores and Ataris of the time had very clever ideas about expansion. The intelligent peripherals are a brilliant idea and we should have done more of that.