Stereotypes always have some truth to them. They aren't really similar to pit bulls in mentality, pit bulls are primarly fighting dogs. Rotties are guard dogs inherently, so they don't usually initiate the attacks, they protect (their owner, their territory, themselves etc.) and they're pretty damn good at it. I personally have never owned a Rotty, but i lived close to one and that was enough for me to not want that breed ever. My dog was almost killed by a Rotty, my friend's dog also almost got killed by not the same Rotty, but a different one.
I guess a lot depends on how you train the dog and every dog is different, but some things are hard wired into the brain and this breed can turn hostile really fast maybe not against you, but other dogs, other people, your neighbors or even your children, so pretty much anything which is not you and not respected by it. I would never be comfortable to have my kids around a Rottweiler.
Another thing you should consider: Are you strong enough for an adult Rottweiler? Because most certainly there will be situations, when you need to hold it back with not just words, but your physical power.
You do as you please of course, but unless you live in some dangerous place or you're someone who needs this kind of protection of a primarily guard dog, the Lab would be the wiser choice and an easier dog to live with.
Plus Rotties eat a lot lol, you need to calculate with that too.
Owning a Rotty comes with more responsibilty than owning a Lab imho.