I've had every iPhone since the beginning, and never had a home button issue.
For some reason Apple decided to get cheap (Probably to increase their profit) and put a very poor home button in the iPhone 4.
I'm on my fourth replacement iPhone 4, all replaced by Apple. Already the new one in less than two months is acting up. This is simply unacceptable from a premium company like Apple.
Yet that said, I am fully aware that all they care about is bragging rights as the company with the most money, power, and influence.
They are _Not_ the company they once were when it comes to actually caring about their customers.
At the genius bar, depending on who waits on you, they do have some latitude as Apple is overflowing with the funds to do goodwill replacements even when out of warranty. That's how I got the last one, but I'm not counting on anything in the future other than the failure of these incredibly cheap mechanical buttons.
Why Apple would use old school tech like a mechanical button on a terrific touch screen device is odd indeed.
The touch sensitive buttons on my Androids are wonderful and there is nothing to be concerned about. Dirt and dust proof they do what Apple claims "they just work". Android is far better than many give credit for .
I like both Android and Apple, I'm just really disappointed in the "New Apple" with some of the stunts they pull.