Sounds like my decision to go to the little Odyssey/AGM PC680 was timed right as my Optima is about 7 years old though only in use 4-5 years. It's probably at the end of it's life, though it is sitting on my work bench with a charger on it after testing fine after its 'last start'. From what I've gleaned, once you kill the Optima's charge, it can be a bear to bring it back to life, though it is possible according to one article I've come across.

What I like about the Odyssey as well as the XS Power 680 size, it's a bit less then 1/3rd the size of the Optima Red Top 24 which opens up lots more space for me in my trunk plus has given me an incentive to clean up some less then great looking wiring - yeah, I know! I was gonna move it out of the trunk, but after making up a box, and starting the new wiring runs, just wasn't happy with the location next to the gas tank.