I am switching back from 4s to Android because I find Safari unreadable with my old eyes. No control over font sizes, and the double-tap zoom doesn't reflow text. So HN is completely unreadable in portrait, and only barely so in landscape. No problem on my DroidX.
Have you tried "Reader" mode in Safari? An icon shows up in the address bar when Safari detects that you're reading an article - when you press this icon, the page appears as simply formatted text and it gives you full control of font sizes.
Of course, since HN isn't an article, it's not much help here - HN is the one page I use where this is a problem, ironically.
Goddamn reader button doesn't show up in half the places I would like to be. I don't know why they still haven't implemented text-reflow like most other mobile browsers.
Why was this downvoted? This is a clear shortcoming I noticed on ios 4 before I switched to Android. Safari doesn't reflow text on double tap and you have to scroll right and left to read an article. From a usability perspective if I double tap on text I want to do some reading and it should be reflowed. The reader button in ios 5 rectifies the issue but it is still not as natural as reflow text on double tap.
I am switching back from 4s to Android because I find Safari unreadable with my old eyes. No control over font sizes, and the double-tap zoom doesn't reflow text. So HN is completely unreadable in portrait, and only barely so in landscape. No problem on my DroidX.