I want to think further about this but my preliminary thought is that what you're talking about is not something that ends up being "higher" or "lower" but something that gives measurement to the "intensity" of the pleasure.
I know Elayne has discussed this before and "intensity" and "duration" both fall short of being full descriptions of what we are talking about, but clearly pleasures, while all sharing the same nature as being felt as pleasure, do differ from one another in important respects in terms of how we feel them.
This is a deep subject that we haven't really addressed, and although I certainly see where you are going with "meaningful" I suspect that's also going to fall well short of an accurate description. And i am not sure that "meaningful" may not even be less useful or descriptive than "intensity' and "duration" - it is almost as if the word "meaningful" is kind of circular.
Probably this also is relevant to one of the more difficult PD's, but apparently one of such importance that it was in the "top ten":
9. If every pleasure could be intensified so that it lasted, and influenced the whole organism or the most essential parts of our nature, pleasures would never differ from one another.
We rarely talk about it because it seems so difficult to be sure what it means, but I bet it relates to this discussion.
Edit: Also, in order to avoid violating the rule that Pleasure is the highest good, we can't really have a standard outside of pleasure by which we judge pleasure; it seems like any word we look for has to be an attribute of pleasure itself (eg, duration, intensity.....) because otherwise if the issue is some outside standard ("meaning"?) then the goal of life must then be expressed as "meaning" which obviously blows a hole in the side of the logical analysis.