As I use Next.js for more than one of my web projects and plan to keep using it for new ones, I have migrated from Netlify to Vercel.
Vercel owns Next, Netlify is a pain when making changes to the builds that involve Next, and it's been a bottleneck plenty of times. If there is one thing I hate more than anything else when building for the web it's messing around with configuration files and labyrinth documentation and Stack Overflow threads.
Instantly, Vercel feels faster and easier to navigate. All my DNS updates happened nearly instantly, SSL was automatic, deploy previews in GitHub happen automatically. Everything is just more cohesive.
When tools get out of the way and just work as expected I am more inclined to build things. I get zero joy from overcoming blockers that don't actually move things forwards. The time spent doing this migration will be repaid many times over.
EDIT: I have to break my no-edit rule to add that the build for this site (which happens twice a day) usually took around 90 seconds on Netlify. On vercel it's 18. That's a 5x improvement.