Shedding
Their coats shed differently: the Soft Coated Wheaten Terrier sheds through the year, the Standard Schnauzer holds loose hair until it is brushed or clipped out.
Grooming
The Soft Coated Wheaten Terrier needs more grooming, brushing a few times a week, where the Standard Schnauzer needs a brush once a week.
Temperament
They differ most on affection (Soft Coated Wheaten Terrier: a lap or leaning dog; Standard Schnauzer: affectionate on its own terms) and on loyalty (Soft Coated Wheaten Terrier: bonded to its family; Standard Schnauzer: sticks close to its people).
Alike
They are much the same size as adults, about 16 kg (35 lb) for the Soft Coated Wheaten Terrier and 17 kg (37 lb) for the Standard Schnauzer.