Legion of Super-Heroes #308 was the middle chapter of the Omen/Prophet storyline, an arc which has typically been much maligned both at the time it was released as well as looking at with the passage of time.
Does it deserve such vitriol? Reading it now, I will admit it isn't a great story. It probably isn't a good story. But it isn't a stinker. I think the reason it suffers is because it was released just after one of the highest points for these characters. It has to pale in comparison. Nothing gold can stay.
I also think it suffers because this is the first time we see Giffen's new style of art. It isn't polished. It doesn't have the organic lushness of his earlier issues. And it is new. After basically two years of brilliant style, readers had to get used to this new look.
And one more thing, the villain here ... the Prophet and the Omen ... they just don't have that personality that we Legion fans have come to expect. These were just powerful beings tromping through. I can't help but think of them as the poor man's Galactus and herald.
This issue, in particular, suffers a bit from 'middle chapter syndrome'. Not much happens.
Still, I think if I read this story in an Outsiders book, I'd be satisfied. It just doesn't sparkle the way this book had.