Seedream 5 Pro and FLUX.2 Pro are the models the Site’s Seedream and FLUX generators are wired to, and in Vizify’s generation catalog their entries match line for line: 1K or 2K output with 1K as the default, and up to eight reference images. Their generator pages match too — a prompt box, a 1K/2K picker, and Auto, square, landscape, or portrait framing, with no reference upload on the page.
That leaves the families. Seedream 5 adds Seedream 5 Lite, which lists 2K and 4K; it is the only model on either side with a 4K entry. FLUX.2 adds Flex, with the same 1K/2K and eight-reference limits as Pro, plus klein 4B and klein 9B, which run at 1MP, take up to four references, and add a 21:9 ratio.
So the decision is less about the two Pro models than about where you may go next: toward a 4K render in the Seedream family, or toward the 1MP klein variants in the FLUX family. Either way, the same free image allowance applies — two generations per signed-in account, then Pro or a credit pack.