I tried it out. Not a massive difference but at 10MHz (in reality ~8.6MHz) the delay between bytes goes from 1.36us down to 1.24us. I didn't notice this before as I was looking at much longer buffer being written and couldn't see CS go high again but if I write 32 bytes of data that is complete in ~80us but the chip select is held low for 2ms after that. I think that's probably a bigger issue than the delay between bytes. :)
