I don't know that I would consider it a "rules based standard," but I think we have to all face the question and answer for ourselves whether different types of pleasure are in fact interchangeable, or whether they differ in at least intensity, duration, and location.
And are those three considerations the *only* distinctions? I think probably not.
What I see us discussing here is that while all pleasures are not reducible to atomic "pleasure units," it is still essential to confront and answer for ourselves whether our rankings of them are totally subjective whims of the moment, or whether they are linked to repeatable and regular bodily or mental phenomena that can usefully be described in repeatable observations, or what.
I do think that it is useful exercise to at least in our individual capacities examine how we want to answer those questions.
My bright line is drawn that I think it's totally inappropriate to take "my" measurements of relative values of pleasure, and presume that my own measurements apply to other people, or that there's any natural design to "maximize pleasure units for all" -- that kind of thing. "The greatest good for the greatest number" has always seemed to me to be a prescription for total monotheism / authoritarianism.
But short of that, I think the exercise we're engaging in is useful, at the very least in that it emphasizes this bright line where I gather that (apparently) the Benthamite utilitarians went far afield.