There is actually a storyline. The story goes forward. I don't know if I would watch it again, but I can't say I didn't like it either. I found it interesting to watch and, although I something wondered if things couldn't go faster, I never despaired. Yes, it is somewhat too arty, but not pointlessly so. It is, finally, the true -if not necessarily adequate- portrait of the character's feelings and thoughts.
What I don't know is if I would have known without prior explanation that they are bored to pieces and that that's the reason their sex is so bad. Because it IS bad. You don't see real pleasure, just some horniness at the beginning and naked bodies at the end. This is not something I would call avantgard or outrageous, as they call the film. There is nothing daring in it. Just some lousy, fragmented sex and that's it.
But the question about being there a story or not doesn't really arise. There is one. The real question is rather if there is a plot! Because yes, the characters go from a to b without hindrance, having to change mindsets, learning from their experiences or becoming somebody else. It is a cut into their lives, a piece of it in a certain moment, that shows how they feel and go about it to have some emotion, some change without it affecting the innermost structure, because it simply can't be otherwise. There is no drama about it. It is so. Just like that. So, in the end they are shown, quite unsurprisingly, walking away and fading into the landscape. They will keep on walking no matter what they do. The film wants to say that even sleeping with someone is uninteresting when there's nothing to gain and nothing to loose. You are careless and unattached. And that leads to boredom.
The film says all those things. So it does say what it has to say. The point here is how it does it. And there's why people find it boring.
I wouldn't say it is a *good* film. I'd call it interesting. Not a Sunday afternoon movie, but watchable.