The 6Tl can be brought back up more times becouse of their plate construction, they usually have 225 min. reserve capasity and becouse of the biguer size of the case can acumulate more sulfation before it becomes a problem they do not have as good an CCA rating about 700-800 price about $125-$225 acording to supply source and menber here in SS.
A few other examples for comparizon, The AutoZone Duralast GOLD GROUP 31 for example can be had with much higher CCA of 800-900 and 190 min. reserves, but ussually only one year full replasment warranty they fit the CUCV battery trays for about $95. You can also opt for Autozone Group 65 Duralast GOLD that will have 1000 CA, 850 CCA, 150 min. reserve 3-4 years replasement and about 7 years prorated but you have to make up 1 1/2" for their short height , price at about $115
Atleast Some of The Sears Platinnun Batteries are made by ODESSY'S ( ?) the orange case premium batteries and are about $200-250 or about a 1/3 less when sold under the Sears lavel