They all are excellent schools, and major employers recruit heavily from all of them. Ann Arbor is a mid-sized college town with lots to do and see with the university as the focus of the town. Austin is a larger city with a huge tech and music culture plus state government, but can be beastly hot and humid in the summer months. USC’s location in LA if fine in the immediate area of the campus but questionable if you go a little further, plus you have the pollution and congestion of LA.
Ann Arbor gets cold - usually in the 20’s/30’s during Jan/Feb with an occasional drop to single digits but is quite pleasant in the fall, spring and summer (rarely above 80 deg) . Snowfall is modest and doesn’t affect you much as a student unless you commute by car (buses are free to UM students) , it rains and is overcast a lot more than in California but it is also much greener.
Most Californians get used to it quickly and enjoy the snow. About 6% of the student body are Californians, so I don’t think it is much of a barrier, and midwesterners are a bit more conservative and much friendlier.