The problem with the iPad ecosystem is that the apps (that we cared about) are "cloud connected" so you have to upgrade them to the latest versions to continue to access the cloud content. The content hasn't changed, but the "upgraded" OS required to run the "updated" apps (which, themselves often do little more than deliver a video from a website), bogged the iPad One down to unusability.
To clarify, this is the original iPad released in 2010, the nice big heavy one with the screen that never cracked, the built-in 3G radio that worked great for non-video content, the long life battery, and the bulletproof back case.
We got a mini when they came out, and it lasted pretty well, but was not as durable as the iPad one, not by a longshot. Then, when the first mini died, we replaced it with another mini and that one self-destructed within less than a year - same kids using it, more gentle with it than they ever were with the iPad one, but the new minis are made like tissue paper in comparison to the original iPad.