Sold my personal one only two months after I bought it because it was so slow, even with iOS 7.1.2 on it.
But we have one we use on stage at work for controlling AVL equipment and sometimes acting as a stand in POS iPad for the store. It was on iOS 7 and ran pretty well, but had to jump to iOS 9.x to work with our new payment system. So far it still runs well for it's intended tasks (stage light control, audio controls, video switcher, POS apps, VNC/Remote desktop, some Safari). I did have to turn on reduce motion and increase contrast to make the UI more "useable" so I don't hit things while it's still loading. That helps tremendously.
Facts are: The A5 is slow, it only has 512MB of RAM, screen is 1024x768, and it probably won't get iOS 10. But for what it does, it's fine where it's at. We still have an iPad 1 that sees service as a PDF reader 😎
As far as holding up goes, it's been dropped more than a few times and has some dents and dings, but no cracks thus far. Seems to hold up well for the abuse it can take. Same goes with our iPod touches that serve similar duties.