The possibility of reducing alloy scattering in MBE Ga1-xInxAs has been studied experimentally by growing modulation doped heterostructures (A) with an InAs/GaInAs superlattice 2DEG channel, (B) on a vicinal (110) InP substrate, and (C) with a strain compensated pseudomorphic channel. The maximum 77 K mobility obtained in each case is (A) 60,600, (B) 69,300, and (C) 123,100 cm2/V⋯s, using x=0.50, 0.53, and 0.80, respectively. Partial alloy ordering is observed in case (B). Cyclotron resonance measurements indicate that the reduction of m* contributes much less to the enhancement of mobility in case (C) than the alloy composition factor x(1-x). Alloy ordering may also be important.