Looks like I was conflating ratings. The Deka has an RC of 175min. The AGM listed above is 220min. I was just trying to figure out the reasoning behind paying 4x for the battery.
I guess everyone has their own rationale for things they buy, but I just choose to run one battery and my choice may just come down to peace of mind. Its a premium battery with solid specs and a great warranty that has served me well in multiple vehicles so that is my personal justification. I also don't find the price very high comparatively. I just had to replace my wifes IS350 battery in a pinch, and the group24 duralast gold was $220. Would I trust that battery to run a winch or fridge, camp lights over night and start the next morning in the middle of nowhere? No, but I have confidence the X2 will.