Your brain can't handle more than 5 words of context, but it can buffer up multiple lines? If you've got some evidence for this, I'd be interested, but it seems like you're just making things up at this point.
> I've read hundreds of novels on small screen devices over the last 12 years. So maybe it requires a little bit of adaptation.
It requires adaptation because it's less comfortable. Saying the iPhone is a more comfortable form factor than a small tablet/ereader is like saying that this is a more comfortable dictionary: http://dictionaryperson.files.wordpress.com/2011/03/lilliput....
> But with this adaptation I much prefer the size of softcover books and phones over hardcover books and 6" e-readers, let alone 10" iPads.
A 6" ereader already has a smaller page than about 99% of softcover books. You can't lump together phones and softcover books based on size unless you're talking about those Lilliputian dictionaries. Seriously, pick up a Nook at your local B&N and hold it up next to nearly any paperback on the shelf. Even most mass-market paperbacks have larger pages, and trade paperbacks positively dwarf the Nook. You'd need two Nook screens to equal the size of a page in a Harry Potter trade paperback.
Because the lines are so short, when you're reading the word at the end of the line your eyes have already picked up the context from the beginning of the next line down.
I've read hundreds of novels on small screen devices over the last 12 years. So maybe it requires a little bit of adaptation. But with this adaptation I much prefer the size of softcover books and phones over hardcover books and 6" e-readers, let alone 10" iPads.