I just pulled the trigger on PDF Expert and am inspired to write the review.
The checkerboard effect and clunky and slow feel when going between pages was annoying with good reader. I thought it was my iPad and I just bought a pro, but it still does it. Even free adobe reader provides a better , smoother scrolling and reading experience.
If good reader were smoother and faster, similarly to PDF Expert, it would be a tough call. but for now I would recommend PDF Expert despite the price tag.
Carlninja about GoodReader PDF Editor & Viewer, v4.12.1