The problem these days is the enormous range of things published -- from greeting cards, novels, textbooks, to multi-volume encyclopaedias. This is compounded by print and digital versions. Therefore developing a program that functions ideally for everyone's work is always going to be difficult if not impossible. The features felt to be necessary will vary with each publisher and user.
My initial download copy was obviously buggy and I now realise it wasn't functioning as it should. Once I realised this and re downloaded it, all became clear. To my mind, I think of the Master pages as they currently are to be more like templates. Once you have created a template you can insert this into a page. These 'set-up' pages can then be used like masters and duplicated. If for example you are setting up a 12 chapter book, you can duplicate the pages for the chapter opening page and body pages and simply fill in the text boxes as you go. All opening pages for example will be set out exactly the same.
Over all, this is good for a beta entry and is workable especially I think for short documents such as magazines or booklets but perhaps not so ideal if you were publishing a set of 20 illustrated encyclopaedias! Hopefully, when other features are live and newer ones added this will be great.
I hope they add autoflow with pages and text boxes inserted to accommodate overflowing text, a preflight and the ability to import doc or docx and pdf files. I notice the 'place' feature is there but not operational at present.