Shedding
Their coats shed differently: the Clumber Spaniel sheds through the year, the Labrador Retriever moults most as the seasons change.
Grooming
The Clumber Spaniel needs more grooming, brushing a few times a week, where the Labrador Retriever needs a brush once a week.
Temperament
They differ most on affection (Clumber Spaniel: affectionate on its own terms; Labrador Retriever: a lap or leaning dog) and on independence (Clumber Spaniel: cooperative, with its own ideas; Labrador Retriever: keen to work with you).
Alike
They are much the same size as adults, about 30 kg (65 lb) for the Clumber Spaniel and 31 kg (68 lb) for the Labrador Retriever.
Alike
Both are rated the same on handler demand: suits a first-time owner.