I would guess that the left out part was that BB does provide a 10 year warranty, quality assembly and perhaps some cell matching. They may also have access to higher quality cells since they buy a bazillion of them.
That said, I enjoyed my Fortune 60 Ah build and have no regrets:
For my application I wanted to build a semi-portable system capable of running a 1500w Inverter. Most parts are on the way so here I go. This is also a "proof of concept" thing for me and if I do a second, non-portable install down the road I could easily use the same devices powered by some...
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