The 6TL's the military uses are made by Interstate, not Delco.
I just purchased six of them for my three CUCV's. It makes a huge difference.
And your truck will thank you if replace your batteries in sets.
The 6TL's ARE more expensive. But they do last longer. One set I traded in were dated 2004.
Most folks can't afford to rebattery all their trucks at one time. I got lucky as the wife had the buck left over after paying taxes this year. And it has made a huge difference in starting all the truck.
And when you replace the battery (s), clean the tray and then hit it with a fresh coat of paint.
Regarding the batteries that leak. JC Whitney has battery tray pads that absorb those leaks. They are $10 each, so each truck was $20, which is not that bad.