Anyone here that use NextJS?

Yeah Next.js is alright - depends on the kind of infrastructure. Nuxtjs is one of the better for server-grade shit.

Next.js is definitely pretty good ngl, I tried it for doing clone websites which are (useless for portfolio now btw) loved the routing, folders were quite easily organizable not much of a mess, fast, if you plan on working with tailwind you're going to mix them pretty good other than that great and definitely depends on industry demand in your region but would even call it somewhat "future proof" I guess.

Nextjs is quite good, especially with the new Server Components

I would recommend using the new App Router over the old Pages Router, as it seems just all around better to me.

I've just started with React but keep hearing about Next - can anyone comment on which is pros/cons?

yes I like it too
what do you want for?