Thank you for your post Godfrey. I'll try to clarify few things and explain in more detail where I suspect our points of view differ.
Firstly, this:
For something to be a pleasure, by definition it must be felt. With this in mind, a "background state" could easily be misconstrued (and typically is, outside of this forum) as a "neutral state", even though I don't think that's what you're saying TauPhi .
I am strongly opposed to the idea of a "neutral state". I agree with Epicurus that there are only two distinct states (pleasure and pain). Katastematic pleasure, in my understanding, has nothing to do with neutrality. Quite contrary, it's felt constantly throughout one's life and is sometimes disturbed by pain caused mainly (but not only) by fear which distorts our perception of life's experiences. So, in my mind, katestematic pleasure is synonymous to background noise to life or a will to live or healthy release of dopamine in our brains. It is close to @Don's metaphor of an ocean (if I read it as intended) or mine of a forest which I made sometime in the past. It's what makes us want to experience life.
Which brings me to your next observation. Here we definitely see things differently.
But, to me, this mustn't be considered simply background noise, and it still consists of intensity, location and duration.
"Background noise" might not be perfect description of katastematic pleasure but I hope my clarification above gives better picture of how I see this kind of pleasure. I treat it separately from every other pleasure (for me every other pleasure is kinetic) and I deprive katastematic pleasure of duration for a reason. The duration is there but the pleasure lasts exactly as long as our lives and ends with our death.
If katastematic pleasure would be fleeting and unstable and lasted only for some time, k/k division would make no sense and would be reduced to an absurd. I mean, how much time do we need to declare a pleasure long-lasting so it's katastematic and no longer kinetic? 15 minutes? Two days? 5 years? At this point we might as well start discussing which superhero is better, Superman or Spiderman?
As far as the remaining two descriptors are concerned (location and intensity), I have my reservations as well.
Location is simpler, so I start with this one. Katastematic pleasure, they way I understand it, is located in our minds. By that I mean our minds, if they are healthy, interpret our lives as a pleasurable phenomenon.
Intensity is the descriptor I have the most problems with. And it applies to both katastematic and kinetic pleasures. In my eyes, this descriptor is too vague to be considered a good descriptor of pleasure. Which pleasure is more intense? Eating strawberry ice cream or watching sunset at the seaside? There is innumerable variety of pleasure and all of it is unquantifiable. How can we say that one variety of pleasure is more intense than the other? Ice cream is 5 and sunset is 3?
Even if we consider only one variant of a pleasure, let's say watching sunset, and try to establish intensity levels we hit the wall quite quickly. Watching sunset for 2 seconds is less pleasurable than watching it for the whole minute? If yes, by a factor of what?
So, I say yes to variety of pleasures but I'm not too sure about intensity of pleasures.
(Think of times when your body feels really great or your mind is really clear. For me, these times are fleeting. If they're long lasting for you, tell me how you do it!)
I wish I could tell you how I do it but, unfortunately, I don't so I can't. And I hope I was clear about that katastematic pleasure is neither of these things, in my humble opinion. I treat both clarity of mind and healthy body as kinetic pleasures. No matter if they last a day or a year. (Well, a year in my case is just wishful thinking at this point. I'm too old for that kind of privilege.)