I've had a yellow top Optima for over ten years. Simply amazing. It has been in two buggies and now in my dad's Rubicon. It has gone extended periods without any charging and was still good. That said, I have drained it and it was difficult to get it to come back to life. It seemed to take a charge and lose it, repeatedly. Can't remember what I ended up doing to make it hold a charge, but I was able to.
I have read several threads on different forums about how the quality of Optima has declined. If this is the case, clearly my battery is from a different time. The Ford GT's we get at work all have a black top Optima which says Ford GT on the label. Ford obviously believed in them for their supercar. When we get a GT that is wrecked to the point of having a ripped apart harness, multiple shorts, etc. the batteries are generally dead. They don't come back to life. I am not sure what makes the black top unique amongst the others, but they do exist. Possibly it is just a packaging difference, possibly they were only available from '04-'06 when the GT was being sold.
Any time we get Viper's with an Optima, the boss keeps these for his fleet of personal vehicles and farm equipment. The Viper's have all had red tops, although I do not think this was a factory option. We have nearly a dozen sitting at the shop. Some of them can be revived, some don't need to be, some are a lost cause.
I am in the market for a battery for my new buggy, but I think I may try something different personally. I have read great reviews on the Odyssey brand and will probably give one a try. If the rumors are true that Optima has declined in performance and value, I think it would be worth looking at something that hasn't had all the bad press.