This part is irrelevant - you can render any document size on any display, it is 'only' the question of readability. On a 3.5" display you are talking about sub-millimeter sized letters, and if that's acceptable, I'd like to ask for a second opinion from your ophthalmologist Seriously, try it out on a N900 if you can, for example in terminal, you can use *really* small fonts but it's not pleasant at all, especially for prolonged use (like books and publications). And it's not the point of not having enough pixels, stuff simply gets so small you literally have to look at it like a baby, having the device 10cm from your eyes.