Originally Posted by linglingfool

Recent reports from coworkers indicate the bus ride can take upwards of 30 minutes door-to-door, so I wouldn't risk the 90 minute connection if you're on separate tickets. If it were all on one booking, I'd feel more comfortable about it.

That said, UA doesn't participate in the airside bus program, so you'll have to walk 10 minutes to T3, which will cut down on some of the margin.