They're made by Johnson Control, who are the same manufactures that make Interstate and Diehard. Interstate batteries are considered by many as the best battery. A Kirtland (Costco) is the same battery.
This got me thinking, How much difference is there in batteries? Are they all built by a handful of companies, and then marketed differently.
For example, I know their is no difference in Napa batteries (bronze, silver, gold) other than price and warranty. Basically, if you buy the better battery you are just paying for the better warranty.
So I started looking around the internet and found this:
Johnson Controls - The Manufacturer.com - Promoting best practice in Manufacturing
"Johnson Controls now supplies original equipment batteries for leading automakers, including DaimlerChrysler, Ford, Honda, Nissan, and Toyota. A stable of leading battery brands, including DieHard, Duralast, Interstate, ProStart, and Everstart, along with others, all bear Johnson Controls signature. Aftermarket service is also important, and customers represented in this segment of the market include AutoZone, Interstate Battery, Sears, Wal-Mart, and Costco.
There is also a special synergy with the spiral-wound AGM battery that Johnson Controls produces under the brand name OPTIMA. "
The other info I found on manufactures was Exide. From what I can tell, Exide and Johnson Controls make almost all the batteries for sale in North America.
So, basically, you are most likely going to be getting a Johnson Control or an Exide battery. With that said, pick which one you want of the two, and find a good local distributor that has support where you travel and a good price. For me, it is Interstate. For others, it might be Costco, AutoZone, etc. It looks like we are all getting the same batteries from two different sources, just with different labels.
(and, I know, the Optima series, which has very different construction techniques. )