I bought a defender series iPad cover and it literally lasted one year. I use my iPad everyday, but it literally fell to pieces. The hard plastic holds up, but the rubber around it will not last. You can buy (yes, buy) a replacement part, but for the cost, I would buy a liefproof case.
Not real heavy, just bulky. You can leave it behind, but it will only protect from scratches. The rubber part or sleeve comes apart after a few months. My lasted exactly 12, but I used the hard cover every time.