I would say the Labrador is the better family dog, unless you really want to be out excercising the dogs. Seems to me that the GSP ( wonderful breed by the way ) is a bit more high energy and requires more run time.

My young lab needs his fair shair of time to run, but he is really pretty mellow in the house, and calming a bit more every day.

The breeder I bought my dog from asked me several question and I realized that my dog was going to be 85% family dog, 15% hunting dog. He has a wonderful pedigree, but I did not take the 'hardest charging' dog from the litter. A real go getter in the field has a tough time containing his energy in the house.

The lab is a favorite of mine. I would like to have a GSP or Viszla as well, but as I go through the process of training a good, aggressive field trial dog, it makes me wonder what one of the more high energy dogs would be like in the house.