Next.js App Router — 8 Months In, My Honest Assessment

Data fetching is dramatically better. Async Server Components meant I could delete entire layers of getServerSideProps boilerplate. Co-locating the fetch with the component that uses the data is cleaner and easier to maintain. The layout system is also a genuine improvement — nested layouts that persist across route changes without re-mounting are something I'd been duct-taping together in Pages Router.

Loading UI and error boundaries per route segment — finally. In Pages Router you handled these at the page level at best. Now I have granular loading states that match the actual component tree.

The 'use client' boundary was the hardest conceptual shift. It changes how you think about component composition. Moving existing components over required auditing every useState, useEffect, and event handler. Some components that looked simple required significant restructuring.

Third-party library compatibility was a real friction point. Several libraries I relied on used browser APIs during render and didn't work in Server Components. Some had been updated for App Router, some hadn't. Debugging those failures is not beginner-friendly.