Oooh - Long and Sedley go in the Monadnock direction - interesting.
Given the apparent contrast that is being set up between the first and second parts of the sentence, seems to me that the direction stated by Bailey and the majority make the most sense.
Of course I readily admit that I am "expecting" to see Epicurus say something like that given his devotion to pleasure in what appears to be the ordinary sense of the word.
With all due respects to the ascetic viewpoint, it will never make sense to me that Epicurus would have held that the most important thing to do in the brief interlude between an eternity of nothingness before birth and an eternity of nothingness after death would be to emulate that same state by denying oneself pleasure in the ordinary sense of the word while alive.
I therefore don't think Epicurus did that, nor do I think he could possibly have taken the Greek and Roman worlds "by storm" if he had. Where texts appear on uncertain on the role of pleasure and asceticism, I would accept the more likely as the one that more clearly reflects the shortness of life and the central place of pleasure, given that we are looking at the statements of a man who claimed to value reasonableness and consistency and - above all - clarity of expression in his statements.