Frankly a no brainer for me, CU Boulder has the better AE program and you’re already admitted. As long as the cost isn’t an issue then go to CU. As far as a party school, engineers don’t have the same amount of free time as the school of arts and parties, its always interesting when someone asks about the party scene as if they would be forced to participate.
Also CU Boulder is a “recruited school” for aerospace engineering so getting a job in CA shouldn’t be a problem.