SU is a really good size. I will leave my dorm to go get food and I'll see people I know and people I don't. Its big enough that there are lot of majors and classes to choose from but small enough to receive individual attention from the faculty and staff.
There is a lot of support for students. Each floor has two RAs and one LLC mentor. The dorms each have one Jesuit living there, one minister and one Resident director. There is always someone to lean on if there is an issue. On top of all that, there's a health center, a counseling center, and plenty of other places to get help if you need it.
Some things I'd change: Library closes at 6 on fridays! And at 11 or 11:30 other days. There's a twenty four hour computer lab and ready/studying space though. Also the main cafeteria closes at 7:30 on Weeknights and 7 on weekdays. Theres a cafe to get food after that but the menu is limited. Sometimes the wifi isn't that great. A few wifi spots broke down the week before finals one time...not so great. Tuition is expensive because it is a private school. I've heard people say that they will have to leave soon because they are not able to afford it. Tuition is often raised too :( Some people say that have gotten good financial aid, some not. It depends on who you talk to. There are some issues with the school going to Division 1 athletics. A lot of students feel like the school should spend the money on financial aid or academics instead of sports, but again, it depends on who you talk to. Also, the night shuttle/safety service shuts off at midnight and it doesn't go very far of campus. Frustrating, because the surround neighborhoods can be a little sketchy at night.
When the library is open, its great! It was just remodeled and it has lots of group and private study spaces. It has a lot of sustainable features too!
The school is great with sustainability. New buildings are made with green techniques. The seafood in the cafeteria is mostly sustainable as well. There are recycling, trash, and compost services in every dorm and all around campus.
SU is in a great neighborhood. The neighborhood can be kind of sketchy but if you walk around with a few friends it is fine. There are lots of awesome places open late in capitol hill (the neighborhood next to campus). From my dorm it is a ten minute or less walk to shopping, restaurants, movie theaters, parks, grocery stores, bus stops, and a bunch of awesome local businesses. Seattle is pretty good about that!
My teachers have all been great, but I hear complaints as well.
Overall, I enjoy it here. Seattle is great and the things I would change about the school aren't huge issues.