Drum Mower or Disc Mower

My operation is at the hobby level, less than 1,000 small bales a year with old equipment.  The tractor I am using is 54HP and my land is flat.  I am finally ready to ditch my sickle bar and move up to a better cutter.  Here is eastern Virginia I do not run across used equipment very often and buying a used disc cutter sight unseen and having it shipped to me is a bit scary to me.  Even if I find one locally I am not sure I would be able to tell if it is in good condition.  I am looking at a new Morra disc mower from Agri Supply or a Tar River Drum Mower.  The Drum Mower costs a lot less than the disc mower and being belt driven I think it may be more reliable than a low end disc mower.  Is my reasoning sound here?  What are the downsides to Drum Mowers versus Disc Mowers? 

Drum Mower or Disc Mower