there isnt any real difference between the two models apart from the frame colour the internals are the same and interchangeable .
the model that is the hardest to get is the ultramag XLII , XLIII, these models have a quick release bayonet fitting on the side of the reel allowing quick spool changes , all of the Ultramag range have one advantage over the 5500c , 6500c type reels in that you can overload a spool and still get it out of the cage whereas on the 55,65 series you have to drop the line level to get the spool out .