I have an 8 year old Optima in my 180 Massey, it's been worth the money. It's showing no signs of giving up soon, but now that I've said that, it'll probably die next week.
When I got my new to me pickup 2 years ago, the commuter car needed a new battery. At almost 280,000 miles (now 305K) I didn't want to spend $100 on a new battery for it, so I put a new Super Start AGM from O'Reilly in the truck and the old battery in the car. It's still going strong, but it's really too soon to make an opinion on a battery. Unlike Randy B, I have ran it dead a couple times, and it's been just fine after recharging. Could be he got a bad one, or the small ATV models just aren't built as well.
Why didn't I buy another Optima? From what I've read on several forums, they switched to Mexican manufacture, and the quality isn't there anymore.
Whatever you decide, a Wal-Mart battery of any price range isn't worth it unless you enjoy having a less than a year old battery die at the most inopportune time. Sure, you can take it in and exchange under warranty, but I like something I can rely on.
I'll keep buying AGMs as needed as long as they keep working as well for me as they have.