Why watch this film?? Brief Response (SPOILERS).
In response to debate about whether this film is as good as/better than American Beauty or whether it is a film of merit I would argue:
The film doesn't compare to American Beauty - for me this film is more universal: the totality of the film's style is more realistic than American Beauty, the despair of the characters is less melodramatic and more mundane, and there is an option for hope at the end of this story which doesnt exist in American Beauty - the known fate and likely consequences for increased separation within the Carver family compared to the opportunity for the "Kline/Allen" family to communicate and return to their earlier bonds was fragile but plausible.
The pathos is more disturbing in The Ice Storm - the father's grief at finding his son dead in comparison to the silent witnesses of the scene was the greatest insight into that character, unfortunately left too late. And the following scene with the Sigourney character opening her eyes at the sound of her husband's cries when you know that she is about to learn that her child is dead was sublime, there was no need for anything further to be filmed there.
The presentation of each generation as subject to the same frailities also distinguishes The Ice Storm from American Beauty - this film doesn't seek to portion blame on the parents for the disconnect but leaves the viewer as a passive voyeur of the broader ramifications of a society in freefall.
Watch this film, is brilliant.