I'm a freshman at UC Davis and I have no problems at all regarding class size. Professors and TA's will allow questions to be asked during lectures far more times than not. And if you don't get to ask your question or don't which to do so, simply go to the professor's or TA's office hours for some one-on-one attention.
If the 400 person class sounds huge, well, it is. But hey, if you sit in the first few rows, who cares? ;-)