Too the best of my knowledge a MP3 disc will not play in most regular CD players, you would have to burn the songs in thier original audio format to use in a CD player.

As for the CD-R yes sometimes they can make a difference, some brands are better than others and some not, I find it the same with DVDs and my burner, I can have the same style DVD but my burner is picky and will only burn certain ones.

someone more quailified in this subject should be along and be able to expand on a answer for you.