There was an interesting article on batteries in a recent Consumer Report I saw while waiting at the tire store. If I recall coerrectly, they said that the same make/model battery could have differences depending where it was sold in the country. They seemed to feel Interstate was pretty good overall, and Diehards were also good, depending on the geographical location purchased. They downd the Optima a bit because they felt it didn't deliver CCA/CA as advertised. I still think that is my next battery, however.
2003 Firemist Red/grey leather SL 500
2015 Palladium Silver/black mbtex GLK 350
1987 Smoke Silver/burgundy mbtex 300E Sportline (SOLD)
Click to see 87 300E