Are you serious ?
On my Mini the pictures are blured (not sharp) on fullscreen view and when viewing with zoom the picture does not load, it is like apliyng digital zoom a small resolution photo. Well, sometimes on some pictures the zoom works and load the full resolution picture but it is slow.
edit: I have found that if i open an album in portrait mode and then turn to landscape mode the pictures are blurier and zoom is not loading 100% resolution photo. Maybe it creates cache for portrait and when turn in landscape mode it uses the same caches(thumbnails at 240x***?) and it looks blurier. For zoom that not work i can't find any excuses.
edit2: It looks like default Album is displaying photos in zoom mode 100% with fewer colors than justpictures. The gradients can be seen. maybe that's why is faster at zooming than justpictures.