These are different players for Blahtune. See the README for each for specific details. A sample tune, using each player, is given below.
IMPORTANT: Files saved from the editor are saved with whatever player was in use at the time. Therefore, to load a song into a different player, use F8 (Load Old File), and recompile the macros. If you use a normal F7 load, the editor will just load in whatever player the tune was saved with -- this is how to load a different player into the editor.
F7 is like LOAD"file",8,1 whereas F8 is like "Load file to free memory and extract all the data out of that file, and stick it into whatever player is currently in memory".
In summary: use F7 to load new players into the editor, and use F8 (and RECOMPILE THE MACROS!) to load old song data into the current player.
Currently, the main difference between players is the raster count. Use the profiler to get min/max/average raster counts.