ive tried out both. next.js focuses very much on the SSR/SSG job, whereas Redwood both stretches further in front of the stack (with Cells and a Form library) and further back in the stack (with Prisma/GraphQL). next is a lot more mature (5yrs?) whereas redwood is new. that help?
Redwood doesn't hide their tutorial behind an account like Nextjs does, they're more user friendly. And it was impressive how smooth it went considering the underlying complexity of the tech stack.