Well, I tried it out after reading this thread and some docs on their site. Really interesting browser, I'm posting from it right now. I would definitely consider contributing to it in the future once I am more knowledgeable.
Right now I'm running Emacs with EXWM, and Next is a perfect fit for it.
My main concerns are security related, I'm not sure if any sophisticated script blockers have been developed for it, and it seems unlikely that support for webextensions will come any time soon (if ever), as the standard itself seems at least partially antithetical to the design of the browser.
As is made obvious by panopticlick.eff.org, by default the browser has poor tracking protection, and so in the meantime I generally won't be using it to post on sites that use JS. That limits me to messageboards such as this one (which might not be too bad, all things considered).