Wow, really?
The outer space shots in it are incredible to be fair.
It's not just that though, the dialogue is very good for a hard sci-fi film - I was critical over the dialogue as a younger man... but after seeing some of the torrid dialogue in some concurrent sci-fi, the mechanisms they put in place to underscore the dialogue is pretty good.
For example, simplest scene ever (and stolen from Event Horizon)... The scene were Bromley explains the concept of wormholes/folding space with a piece of paper and a pen. We all know this concept because it has been brought up in films before.
However, rather than try to explain the concept in an entirely different (and convoluted) way, Nolan simply lifts the paper analogy and adapts it for his film. The dialogue around it is so simple, you could almost get frustrated as a sci-fi fan.
A very simple concept boiled down to a scene. The film is full of them...
Matt Damon's monologue as he and Cooper go to find 'the sites'... It's terribly guffaw at first, and you can't help but feel that if a person was driven to that length, the last thing he would want to do is rationalise it, like out loud... regardless of mission status or the line of command. The bloke is supposed to have been alone for what? 10 Years?
It's pappy, pithy and pretentious all at the same time, but what the dialogue does do, is humanise a very inhuman action (the 'lie') and produces a centrepoint for you as an audience member to choose one moral or another - ask yourself what you'd do. And that scene is possibly one of the most human scenes in the whole film.
People will point to Coop and Murph's communications and goodbye... but no-one here would understand the feeling of leaving a child (potentially) forever. However, we've all experienced that feeling of just wanting to go home regardless of the knock-on effects.
So to summarise - I always thought it was a great, great film. But the dialogue was always a problem for me (it was the same with TDKR, but different)... Time has passed and I can totally enjoy this film, which could be said, to now be in fact, soft sci-fi. Which for me is one of the many successes of the film - it is a hard sci-fi film at its core, but after viewing and in time, it has become a kind of funnel.
Great film...