Here is the response from an email I sent to Odyssey. I wasn't looking for a remedy...just wanted to let them know.

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Thank you for your feedback. We greatly appreciate your taking the time to contact us about your experience. Your question if a valid one and based on the capacity differences between the PC1200 and the PC1400, if the PC1200 lasted 6 years in your vehicle then the PC1400 with a 55% greater capacity should have had a service life of about 9.3 years or longer in the same vehicle with the same usage by comparison. Unfortunately, when you purchased the PC1200 six years ago we were not manufacturing the automotive group size batteries.

Also, you might want to verify that your alternator output is between 14.1-14.8V at the battery. If it is less than 14.1V you may have an alternator that is starting to go. Consistent undercharging or maintaining the battery in an undercharged condition will cause sulfation and premature failure. At less than 14.1V the battery may not be getting fully charged. Just a thought.

Thanks again. Please contact me if you have any questions or concerns.
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I ended up going with the Deka AGM Grp 34 (looks like a debadged Intimidator) and it fit better than the Odessey. We'll see how long it will last, but at least it only cost me $160 vs $300 for the Odessey.