Many people using an RT-style diff mount have eliminated the lower front differential crossmember....it's bulky, heavy, and often interferes with a larger exhaust system.
If you are wanting to eliminate yours, but are worried about negatively impacting structural integrity (between the left and right LCA mounting points), you can fabricate your own crossbrace from suitably-sized flat bar or angel steel. Not as pretty as the T3 unit (like Jon mentioned), but $140 cheaper.