I used to be a fan of spiral Optima batteries but after further research I have found that the new DieHard Platinum are the next generation in battery technology. Consumer Reports comparison testing shows them to be superior to the comparably priced Optimas. They provide (28%) more power, last longer, etc. My optima crapped out just when the warranty was up. Very disappointing!
I'll keep you posted on how it works out. I would be interested in others' thoughts/experience on these.
Here is an excerpt from the Enersys press release:

These premium-grade batteries are designed for a longer life than traditional batteries, offer increased levels of safe operation, can withstand extreme heat and cold, and are durable for consumer automotive/marine applications. The DieHard Platinum battery will offer proven vibration resistance to the consumer market.
The new DieHard Platinum batteries have up to 28% more Cold Cranking Amps (CCA) than comparatively sized spiral Absorbed Glass Mat (AGM) batteries providing much more starting power to automobiles and boats, along with unmatched reserved capacity. These thin-plate pure-lead batteries will carry DieHard batteries' best-ever, free replacement warranty. The DieHard Platinum batteries are manufactured in EnerSys' U.S. manufacturing facility in Warrensburg, Mo, where the first DieHard Platinum came off the production line today. They have a valve-regulated design that allows them to be installed in any orientation ,except inverted, without spilling and the U.S. Department of Transportation has classified them as non- spillable for safe shipping.