This is the most underwhelming experience in the Sect 10 series. A place where nothing happens, and everything is just as it always was.
No one is particularly excited, nor disappointed, about this place. It just exists, like a beige wall in a beige world.
You can find more thrilling content in Sub-01 or Sub-03, if that's your thing.
Sub-Sub-01 is a slightly more interesting cousin, but only by a hair.