I do have to ask why does AA seem to fly 777 and 767s with regularity between MIA and DFW. MIA/LAX which is a premium route only gets a 777 once a day. However MIA/DFW gets multiple 777/767s most days. Add in that DFW/LAX has at least one 777 a day and sometimes 2 777s and with regularity a 788/9 and it seems to make more sense to connect via DFW when flying MIA-LAX. Fares are lower, get widebodies for both segments, and in some cases only add about 1.5 hours in transit time.