I am a Berkeley graduate (but decades ago). Even during that time it was a true nightmare to get into classes (waitlists, etc). If the CS is that crowded / impacted right now – I would be very concerned about the overall experience going through not only the workload stress, but also the additional stress of trying to get a “reasonable” schedule (It is quite frustrating … )
If you are a California resident, the price tag may be such a great value that it is possibly worthy to go through this nightmare. However, if you are indifferent about pricing, then Brown would be probably be a better option. (UChicago is too small and offered courses and opportunities are relatively limited compared with the other choices you have).