Hey Nochal. I'm like you, I grew up in the Ann Arbor area but had never been to the school of social work building until I visited this past fall. The school was very beautiful and modern inside. The building layout seems pretty straightforward, and the commons area seems like a great place to study or hang out between classes.
The class I sat in on was awesome as well. Most of the students were advanced standing or second year students, but at no time did I feel out of place. The professor went out of her way to include me in the class and have me actively participating, despite me being just a visitor.
The students were also very welcoming and inclusive. They did mention that there is lots of competition between students, but that it is usually friendly. That being said, I wouldn't expect anything less from a graduate program at U of M.