My first thought was the same - if it performs like the "page flip" on the Kindle, I'd jump off a high building within minutes. But I've no idea if most of that delay is down to the screen or some combination of processing power and/or conserving power.
The full-page flashing refresh on the Kindle is a software measure to get rid of the afterimage that would otherwise remain on the screen. Here's what it looks like when it's disabled: http://www.youtube.com/watch?v=XQJGfU8fEUg
yeah it's actually not bad, the refresh is only on the character itself so it's workable. If you have a hacked kindle you can test with a terminal emulator, it give you a good idea of how fast the typing be.
