I, too, would be concerned about cats. "Ignores cats" may be good or bad. A skittish cat may instigate prey/chase drive. PBs have powerful jaws. And PBs as a breed have a pronounced prey drive (as do Border Collies, Shepherds, etc.) I'm profiling dog breeds .

With a 800 sqft apt, you may think about a smaller breed that is easily trained (barking concern). An older dog is ideal but I'd rather see a 2-3 year old.

Finally, here is something I witness repeatedly with PBs. People with other dogs react negatively to the "dog killer" and their dog picks it up. The energy (actually scents and body language) is what starts the problems. You often find that the other dog started the skirmish & the PB ended it out of defensiveness.

I have the same prejudices with my 100lb male German Shepherd, but not to the extent that PBs currently have. I do keep a $1M blanket insurance policy because if anybody enters my yard and my dog bites him, I'm still liable.( If the intruder is smart, he'll pick up one of the dozens of tennis balls strewn about & have an instant buddy. ) Not fair, but that's the law. A sign "beware of dog" can be interpreted that you have a dog who is a known problem. It's BS, but that's the way it is.

A CGC on a PB should be mandatory. If you ever find yourself in trouble, showing that your dog earned an AKC CGC (Canine Good Citizen) is a huge gold star in your favor. Plus, it's lots of fun.