An exchange from Facebook:
Poster1: First and foremost it's primary focus is pleasure. That is the means to which happiness is achieved, and happiness is the primary goal of life. But the word pleasure is often misunderstood and mistaken to mean purely physical or sensual gratification. Ataraxia, a state of mental tranquility free from disturbance, is the ultimate pleasure and maintaining it is how Epicureanism is applied. This means eliminating superstitious views that cause fear or disturbance and accepting your own mortality.
Poster2: Can't fill your cup to the rim with pleasure if you're sloshing it all around like a maniac. Ataraxia isn't /the/ ultimate pleasure, it's how happiness is experienced. Happiness is pleasure without disturbance.
Poster3: First we have to say that the greek word "ataraxia" does not go alone, it has to follow and the greek word "aponia". Mental tranquility is in consistency with the body tranquility. Soul and body/mind is one and the same thing, and that means also that the dualism among soul and body does not exist. Second the ultimate pleasure is the pleasure itself, since ataraxia and aponia is only a description of pleasure, when we have to give explanations to those that they do not understand. And third is the term "Epicurean-ism". When someone sees any term with suffix -ism, he has to run away from it as fast as he/she can, since it denotes ideology (political, religious, economical etc etc). Thus, any ideology has nothing to do with Philosophy, and specially with the Epicurean. Thanks and welcome here ! 
Cassius: I was cheering Poster1's post too til he got to the wording of his sentence on ataraxia. Imbufe that is one of the issues everyone has to consider carefully. Most modern books will track exactly what Mike's sentence says on ataraxia, and if you know the technicalities then there is a sense in which his statement is fully correct: Once you have filled your life with pleasure and eliminated all pain, then you want to maintain that state as smoothly as you can without any disturbances. So yes that form of living IS the highest level of experiencing pleasure that you or any human can reach.
Just don't get confused and think that this description implies some different type of pleasure than what you already understand the word to mean. Like Mike gets at, but doesn't maybe state explicitly, the word "pleasure" includes every possible type of mental and physical sensation you find pleasurable, from sex to fine art to fine music to whatever. There are no "good" and "bad" pleasures - pleasure is a faculty which tells you what is pleasing - nothing more, nothing less - and it's up to you to weigh and judge the consequences and decide which pleasures to pursue.
All this is why Cicero summarized the Epicurean position as "a life of tranquility crammed full of pleasures" in his Defense of Publius Sestius 10.23 ("“…Nothing is preferable to a life of tranquility crammed full of pleasures.”)
However, if you check in at the philosophy department of most any college or philosophy group on the internet, and say "Ataraxia, a state of mental tranquility free from disturbance, is the ultimate pleasure and maintaining it is how Epicureanism is applied" you will get an A+
You just have to decide whether your goal is pleasing the philosophy professors, or having a realistic understanding of what Epicurus said about how to live.
Cassius: This is not "pile on Poster1 day" because I think this goes to the issue people see everywhere and not just his post. It's not just the technical use of the word ataraxia that I want to warn about but the combination with the following sentence that implies that all that is necessary to get to this ultimate state is to *subtract* something:
"Ataraxia, a state of mental tranquility free from disturbance, is the ultimate pleasure and maintaining it is how Epicureanism is applied. This means eliminating
superstitious views that cause fear or disturbance and accepting your own mortality."
Again, yes it is absolutely true that we must eliminate superstition (PD1) and eliminate fear of death (PD2). Those are the two biggest false opinions we confront so that is why they are highlighted.
But there is a THIRD false opinion - and that is that there is some goal in life higher or better or to be preferred over pleasure. God and Death aren't the only demons to swat, you also have to swat the demons that there are absolute guides to life such as virtue or "being a good person" or "following god" that everyone must follow. That's where PD3 and PD4 come in, but they are written in a technical way that makes them well-suited for debating Plato, but poorly suited for new students of the philosophy.
Every animal at birth, including humans before they are corrupted by "virtue" or "religion", knows that nature calls them to pursue the various mental and physical pleasures of life. That is a premise of the entire conversation, so you don't get to the best life just looking for demons to swat and subtracting them from life. if you sit in your garden and close off your life with no contact with any ordinary pleasures of mind and body, you have NOT reached the best life. You get to the best life by finding and pursuing those pleasures that matter to you, even if that means accepting some pain as the price. You fill your life with pleasures, make sure you've eliminated the two biggest pains (fear of god and fear of death) and then you are well on your way. Depending on your other circumstances unique to you, your life is both peaceful (free of the worst fears/pains) and crammed full of pleasures.
If someone wants to debate the issue and assert that "ataraxia" is some distinct goal which is separate and apart from the experience of normal physical and mental pleasures, please post here as this is a critical issue to discuss.