Size
The Golden Retriever is larger on average: about 29 kg (65 lb) as an adult, against 22 kg (48 lb) for the English Springer Spaniel.
Shedding
Their coats shed differently: the English Springer Spaniel sheds through the year, the Golden Retriever moults most as the seasons change.
Temperament
They differ most on loyalty (English Springer Spaniel: bonded to its family; Golden Retriever: friendly with everyone) and on handler demand (English Springer Spaniel: needs steady training; Golden Retriever: suits a first-time owner).
Alike
Both are rated the same on affection: a lap or leaning dog.