I personally prefer less slobbery breeds, but I don't think they're dangerous or anything. We've fostered two and they were both sweet as can be, though the one was young and needed a very firm hand because she had the potential to accidentally hurt someone with her jumping, play-chewing, and pulling while on leash. But all of the same can be said of my current dog, a border collie mix.
But I do think, with larger/stronger dogs, it is more important to be aware of their pasts and any triggers they might have than it is with smaller and more submissive breeds. Our border collie was abused before coming to us, and she has serious issues with adult men, especially those who smoke and drink beer, that we learned about the hard way. She bit my husband pretty good once, about a week after we got her, because we were having a few beers out in the yard and he was chasing our 10yo around the yard, playing. The dog decided he was a threat to her favorite person, got between them, and bit his hand. If a dog with the size and strength of a pit did that, it could easily be more serious than some neosporin and a couple of band-aids.