Dalmatian, attractive, independent, intelligent, family loving, natural hoover/dustbin - clears all your waste food. Will make sure you walk everyday, guards the house and hunts vermin. Enlivens your day with their antics, always a story to tell!
No real downsides.
Breeds will only give you a probability, maybe, if you know the parents, a high probability of their behaviour. They do vary. Would definitely research breeds if looking for a puppy, though, even if getting a cross-breed, if only as it gives you a knowledge base to start ie what they may be like, not will esp with crosses. Thing is though, if you want to do mega hikes etc not always a great idea to get a puppy as it won't be up to hiking till its at least a year old.
If you want definite characteristics and aren't fussed about breed, its worth considering a rescue, as they should be assessed, and many (so they tell me) would make great pets, but their (the rescue's) criteria can be somewhat restrictive. Never had a rescue myself (don't think I'm deemed suitable anyway!) but did walk dogs for a rescue centre, and yes, some of them are lovely.