And you can still buy an iPad 2 brand-new, likely for the same price you paid...
Yes, this is true, especially in the past (up to the iPhone 4/ iPad era). Obviously hardware dependent features aren't there (eg siri when new, iOS7 camera, M7, etc) either.
Still, I have zero issues with iOS 7 on my iPad 2 and my parents are happy on their 4S.
My iPad 2 (just over two years old) is a real pain with iOS7, virtually every time I switch apps the app has to restart from scratch