I've had several Diehard batteries die real easy, and suddenly, well before the warrantee was up. Yeah, they pro-rated the goddamm thing on the new purchase (good way to hook you), but if you factor in the tremendous headache this s*it causes, they shoulda paid ME. F*ck Sears. Several states have sued their ripoff automotive end.
It used to be that batteries died a slow death. You could *hear* that it was time for a new battery by the cranking, and not by just getting effing stranded.
I think truck-related battery companies might be a good hedge--Delco, Interstate.
I think tho I'm in good shape w/ my Honda fit, cuz I might be able to start it in an emergency with 8 D cells. :)