The first film is great in it's own way, but you have to be unusually patient. scenes like when she first appears to him are amazing in the original, but the film has a bunch of deficits. It's art is best understood when compared to other syfy films that it was responding to. It was in a way a reply to kubrick's 2001. A message that the alien is already here, it is the world itself. https://www.youtube.com/watch?v=nJiDSbbfk8U
The newer film is more palatable and it's good. It's definitely what most normal people would want to watch. But you're not gonna get those rare moments of choreographic "feeling" that tarkovsky could evoke.
The book is also awesome.