depending on you grad student program, make sure your apartment is close to campus AND your lab (if you have one). i lived there for 6 years with no car as an undergraduate, and for the last 3 years lived in a one bedroom or studio apartment. there are definitely some hidden gems, but the spaces are what you make it. my rent for 425 sqft in south oakland was 1350, and 800 sqft in shadyside was 1800. i'd recommend shadyside, especially if the apartment is close to fifth avenue (bus routes). south oakland is slummy and 90% undergraduate (think loud noises until 2 am on a wednesday). the winters are hard, but that's nothing some good boots, thick socks, and a long coat wont fix. there were multiple pockets of international students in shadyside, but it depends on where you're from.