I wouldn't be scared of either a Brent or Demco if you find one in good condition with a price that you like.    The Brent will usually have a larger/faster unload auger, probably longer/more reach also.   

If looking at a Brent, the adjustable spout on the 82 series is better than the spout on the 80 series, I think that is the only real difference between those.     The spout on the 80 series tends to fan the grain out a little bit when running at less than full flow, if its really windy this leads to grain being blown around easily.