My impression after many years of working with JSF: PrimeFaces or not, it's a lot of server-side state making it hard to work on the front-end and an unnecessary burden on the server.
I have also some nice things to say, and I'm not going to make a detailed analysis here but IMHO, it's really not worth the tradeoff.
Agreed, and yet the celebration of stuff like Blazor Server, Phoenix, among others show that some folks really like this approach.
Personally the experience with JSF and Web Forms, is what makes me appreciate any framework that exposes the underlying browser stack, instead of pretending it is something it is not.
I have also some nice things to say, and I'm not going to make a detailed analysis here but IMHO, it's really not worth the tradeoff.