Not sure if this is better suited for here or for Stack Overflow - a commenter on a post dealing with similar (though not identical) topic on SO suggested that it would have been better to post it here. If this is wrong then I apologize.
I hope you will excuse this somewhat of a philosophical question. I'm an independent/individual iOS developer. Recently, the one device I keep around for iOS 4.x compatibility testing (an iPod touch) gave up the ghost -- and I am having a devil of a time trying to replace it. Of course new devices all have iOS 5 on them. So one would think to hit up the used market. But alas this is proving fruitless. Even the used market is proving little help, as most sellers think it helpful to upgrade to the latest and greatest before putting them up for sale. And after yet another day spent fruitlessly plowing through eBay search results, I finally had to sit back and think to myself:
How important is it to continue to support iOS 4.x?
It seems (at least if these blog posts are to be believed) that pretty much everybody is on iOS 5 these days, since it is still supported on even fairly old hardware; and that supporting older iOS versions will run you up against the law of diminishing returns, as supporting iOS 4 is both costly and largely unnecessary. At the same time, I look at the new stuff we got to play with in iOS 5 (and soon we'll have even more toys in iOS 6) and I can't help but drool. ARC alone looks like it will save me quite a bit of headache. (Hey there retain/release, don't let the door hit you on the rear on your way out)
So I guess what I'm asking you is, as a user, how important is iOS 4 compatibility? Did you upgrade to iOS 5, or are you still running iOS 4.x on any of your devices? And/or do you know anyone still running iOS 4.x? (The stereotypical tech-unsavvy parent comes to mind) Any and all comments/advice/practical real-world experiences/etc. you can provide is greatly appreciated.