It doesn't have any brightness settings, just on, but the default brightness is pleasant for reading in bed at night, it's not too bright and not too dim. (blog.the-ebook-reader.com)
I actually purchased the 8.9 but returned it a week later when I realized that it was a little too big and awkward for reading in bed at night. (blog.the-ebook-reader.com)
I use it daily to take handwritten notes at meetings, but it's also great for reading in bed without tiring my eyes or having to turn pages too often. (goodereader.com)