Yea, only real world experience is going to tell when finding the better cheep lead acid battery.
When I bought my van used I saw the previous owner had problems with Interstate batteries. Therefor I am going to be trying the wallmart group 27 and will report how it goes.
At wally world the rack of batteries have dates on them so I am tempted to take from the back. However I wonder if they don't just change the date stamp and move them to the back.
Here is the box I made for them from a black tool box