I am thoroughly impressed with the pair of AGM batteries I picked up from Autozone (AGM-65 Durolast Platinum) for my F350. Yes, they were expensive ($160) compared to the typical Exide battery from Walmart, but they are built well and have a 3 year replacement warranty. Looking for at least 6 years from them. We shall see!
I am really tired of having batteries die what seems like every other winter. I buy all my other batteries from Battery Systems in Boise. I am gnashing my teeth waiting for Lithium technology to become affordable...