I don't think I have any real spoilers here.
My wife dragged me to it a few days ago. I was expecting heart-warming sweetness surrounding a cute little boy robot.
The opening scene made it clear that wasn't happening, just by the lighting.
The ghost of Kubrik is very present. This is an extremely slow and deliberate piece of cinematic art. Very, very good - but there were four people in the theater that night, and I expect a number of people who brought young children (other nights, there were none this time) were unhappy - the pacing is not child friendly, and neither are some of the adventures and characters.
The usual Kubrik exploration of what it means to be human by means of characters that stretch the definition is there. David (the AI) is a prototype, and loves genuinely, but expresses that love rather coldly and (this I consider a great thing about the movie) never turns cute or seems particularly real. Gigolo Joe (exactly what he sounds like - he's a sex mecha) on the other hand, acts much warmer and is a much more realistic imitation of a human. But his feelings are only simulated.
There are no warm, likable characters.
There is no romantic subplot.
The story is a fairy tale - Pinoccio. It doesn't attempt to be technicaly beleivable.
This ia a very, very good movie. Not a fun movie, not a kid movie, not a date movie for most relationships. This is fairly serious cinematic art.