
I have golden retrievers and they are a completely different breeds to labrador retrievers. Here are some of my generalizations. Goldens are slighty less energetic than labs, more laid back and less in your face towards other dogs. Just calmer overall. They are more senstitive
and more stubborn. Most labs I've been with are more biddable, some goldens are more thoughtful about whether they feel like pleasing you. Of course that's in relative terms, goldens are pretty biddable. I spoke to someone who worked both breeds in field trials and she says she doesn't count on her goldens being totally reliable until they're 4, her labs are at 2 years old. Labs also seem to be more bomb-proof.
When I was looking for my second dog I contacted lab rescue thinking they were similar enough but the rescue coordinator convinced me to get a second golden and I think they were right (BTW she owned goldens but rehomed labs). The Cavaliers at the training club adore my dogs, even the shy little ones. The big guy lays down and lets them snuggle all over him.
Obviously the breeding behind the dog makes all the difference. My goldens came from a breeder who has dogs with fantastic natures and the temperaments i wanted. I went and met the gang, made up of a few generations, to decide if they were my kind of goldens. The pups from my dog's sire tend to be as calm and laid back as him.
Physically the goldens have longer coats than the labs but most labs shed more. My sister has a yellow lab that we call the dandelion. If you do have a GR you have to be prepared to have wet muddy dogs around. At least with labradors you can towel them off easily. Guaranteed, no matter who I walk with my golden dog is always the muddiest and has rolled in the most smelly stuff around. :-D