We have a Labrador (22 months old) from working lines. Both his parents are award winning working dogs, (apologies for the boast, trying to add context).
He is a wonderful wonderful wonderful family pet. He's a typical Labrador- loving, kind, energetic, hungry and willing.
He has been easy to train because as a young dog he worked well for food rewards.
We trained using only positive reward methods. He was initially trained like any other family pet with basic obedience classes and tasks. He reliably sits, lies down, waits for extended periods, walks well on the lead, leaves things that he is told to and his recall is great.
We tried a bit of gun Dog training, (again positive reward based, something that we found hard to find), and wow he loved it. He would now do anything for a dummy, even forgoing treats to play fetch with it, and his favourite thing ever is gun Dog type exercises. He will not ever go shooting but that's no barrier to allowing him to enjoy similar activities.
I don't think he needs excessive amounts of exercise- he gets two short and one long walk a day. He has frequent access to a secure garden, but he doesn't actually do much other than sniff around. On occasion he has had less walks and he has been fine.
He is very relaxed in the house, and sleeps an awful lot.
We have set things up so he is very rarely alone for more than 3 hours. He goes to daycare once or twice a week, and sometimes he comes to work with me and snoozes under my desk in between tummy scratches from the team. I think he would be ok left longer, and more often but I can't help but feel he prefers company so I do make sure he's not home alone much.
The only issue we have had was a rampant sex drive. I did a lot of research and hoped not to neuter him, however he was impossibly horny and humpy to the point that it was becoming impossible. So with a heavy heart we neutered him at 17 months.
Sorry for the epic post. Our experience of a working lab has been nothing but positive. I do sometimes look at the gorgeous and more solid show lines and wonder if the extra mass causes extra joint stress- something to be avoided in Labradors as they are prone to joint issues and as such should be exercised carefully especially until they are two.
Good luck with your decision OP.
We have set things up so he is very rarely alone for more than 3 hours. He goes to daycare once or twice a week, and sometimes he comes to work with me and snoozes under my desk in between tummy scratches from the team.