Shedding
Their coats shed differently: the German Shepherd moults most as the seasons change, the Rhodesian Ridgeback sheds through the year.
Temperament
They differ most on independence (German Shepherd: keen to work with you; Rhodesian Ridgeback: decides for itself) and on intelligence (German Shepherd: needs daily brain work; Rhodesian Ridgeback: learns readily, likes games).
Alike
They are much the same size as adults, about 38 kg (84 lb) for the German Shepherd and 35 kg (77 lb) for the Rhodesian Ridgeback.
Alike
Both are rated the same on loyalty: sticks close to its people.