I have used it for quite some time now, and here is the review.
Pros:
Looks professional.
uncommon way to view images.
cons:
takes little bit more time than acceptable to load images after zooming.
When in landscape mode, horizontal scrolling stops right at the end. however, vertical scrolling goes on and on creating a loop.
Does not offer any text/help file to indicate which keys can be used for what purposes.
For example, I didn't realize that 1 and 3 can be used to rotate the images.
I would recommend this software to others regardless of its bad sides anyway.