What they sell
BigBlue is best known for portable solar panels and has moved into balcony solar with the PowaFree system. The pitch is price: it undercuts most of the alternatives.
Where it sits
Less established in the US market than Craftstrom, with a correspondingly thinner support and warranty track record. For a first purchase in a category this new, that is worth weighing against the saving.
New category, new brands. US plug-in solar is young enough that long-term reliability data barely exists for anyone. Buy on price and specification, and keep your receipts.