I've been a Wix user since '16. But I was reading troublesome things about the New Blog and was hesitant to start using it.
I just finished migrating my old blog to the new blog. Took about 10 minutes. The only thing I had to do was modify some of the new default categories and that Log-in feature.
Other than that, it functions as well as the old blog. S'pretty brilliant.
I don't understand the fuss.