I have a 41.5 lb 1/2 Pit mix(unfortunately don't know what else is in her) and live in an apartment and she does great. I do walk her plenty though. She's very quiet, only time she's ever barked was around the 4th of July from fireworks. And even then it was one single bark and that's it, nothing sustained. There's another dog down the hall that barks whenever I walk by to take mine out but even when other bark at Cleo, she just doesn't care and doesn't make a sound. In ever possible way she's the most gentle and well behaved dog one would want. I couldn't ask for a better one.