I tried the large print edition on my EZ Reader (Hanlin V3) and iLiad.
On the EZ Reader all three fonts sizes were the same, and identical to the standard largest font. This is very similar to the Kindle's 5-th font size, which I attach here (because the EZ Reader does not do screenshots). The difference on the EZ Reader is that there are 5 more lines of text on the page (due to no header, and narrower line spacing).
On the iLiad, the ebook comes up on the largest available font size but this is no different in size from usual and all the other sizes are available. The 8" screen allows a larger font (and the iLiad has more font sizes) than the Kindle. Note that when viewing screenshots make sure your web browser is showing them at full resolution (click on the image again if not).