It's not bad, but I think 343 should have mixed both artstyles to create the real Flood Spartan.
But if the Flood returns in Halo 6, the Infected Spartans should get an proper form, with their own weapon and everything, like Halo 4. Not like H2A, nor Halo 5.
EDIT: I think I changed my mind. I think the Flood Spartan/Sangheili should NOT get a form like in Halo 4. At best, something combining H2A and Halo 5. Halo 4's Flood/Infection customization was a bit underwhelming. To create the perfect Infection, 343 needs to look back at the infection of Halo 3, Halo Reach and H2A (now Halo 5 too), take the best features from it.