* The Spectrum didn't come with a tape player, you had to buy one. The Amstrad CPC464 had a tape player built in, however neither the CPC664 or CPC6128 had a tape player built in, you had to buy one if you wanted to use tape based software with them.
* Both the Spectrum and Amstrad had to use the CPU for loading or saving on cassette. The Spectrum ROM loader used the border colours to indicate loading (especially the use of coloured striped bars in the borderto indicate each data bit) a small block for a header, and then loaded the program with one larger block. The checksum/error detection was done using XOR. The Amstrad's ROM loader used many smaller blocks (so you could rewind if there was an error), it indicated loading progress with text that updated on the display, and used the better CRC for error detection. However, if the loading messages were turned off, you didn't have any indication of loading progress.
* The Amstrad's BASIC and firmware are said to be better than the Spectrum's BASIC and OS functions.