The ratings system I use is strightforward and a tilt of the hat to cultural theorist Roland Barthes. There are texts of pleasure and texts of bliss, these can be simply defined as:
Pleasure (readerly), is writing that doesn't challenge the reader's ego or life views but provides uncomplicated formulaic reinforcement to their expectations, it's pleasurable in the same way as throwing and catching a ball as it bounces off a wall. Its fun, easy and a good way to relax.
Bliss (writerly), is writing that gets under the readers skin and demands engagement and openness to the absence of control the writing represents. There is a lack of reliance on what is 'known' and a willingness to create a-new and transform the world in some way. It is blissful in the same way as crossing the finishing line of a marathon after 6 months of hard training.