Streamed it first to see if it was worth buying on disc, it is.
They have a really cool commentary feature where the image is shrunk to a 4:3 image so they can split it top and bottom.
The top image is the film as presented, the bottom image is the raw footage before visual effects were applied.
It lets you see how much of the film was digital and how much was practical. Complete with commentary.
When I poster this at the time there was a video showing clips of this that isn't showing now, but that clearly shows all the main cast acting together, so the blue screen studio wasn't empty.