As the kids say, it's got great stance, but does it handle better? (vvuzz.com)
Performing back squats with greater stance width seems to involve greater gluteus maximus EMG amplitude (McCaw & Melrose, 1999; Paoli et al. 2009). (strengthandconditioningresearch.com)
Performing deadlifts with greater stance width (using a sumo technique instead of a conventional technique) does not appear to alter EMG amplitude in the gluteus maximus (Escamilla et al. 2002; Sorensen et al. 2011). (strengthandconditioningresearch.com)