I am in the process of converting these files over to HD versions. The HD versions are not put onto templates, are 1920 pixels wide, and include a HD version with a soft edge saved as a .png file. Look for the "HD" designation in the title.
As for the rest of these files, most of these sets contain Standard Definition (1024x768) PowerPoint files in 4 orientations: Title Slide, Full image blended into template design, Cornered image on template design to maximize notes area, and Full image watermarked over template. Most sets also include the base, unaltered presentation-sized image. Exceptions are sets built in Powerpoint such as charts and certain maps with editable information.