To make the text larger than 10-point font requires zooming in on the document and dragging it around with the iRex's stylus, a naggingly slow process given E-Ink's refresh rate of about one second. iRex claims it redraws its screen faster than Kindle, but in Forbes.com's tests it locked up sporadically and often took far longer to refresh than Amazon's less flashy display.
FORBES: E-Books