I've had far more luck increasing segments and mileage on AA using Orbitz than aa.com.
I recently saved about $600 when I needed to go BWI-ELP-DFW-BWI by using Orbitz, which came up with: BWI-STL-DFW-ELP ELP-DFW DFW-OKC-DFW-BWI. 3 extra segments and a bit over 1,000 extra status miles.
When aa.com won't give me a competitive rate (i.e. well in excess of CO, DL, etc. for business purposes), I've had 100% sucess in getting Orbitz to come up with some funky routings to bring down the fare and usually increase the mileage.