As a current first year UCSB major studying CS, all our engineering programs are awesome! That being said, Davis/SD/LA/CPSLO are all academically on par, as far as their engineering programs go. The difference between Davis and SB is the campus life: UCSB is so much more beautiful, the people are so much more friendly, and the weather and food are SO much better. My friends and I aren’t partiers at all, and I wouldn’t say that the huge party scene has really affected usl. All the partying happens off campus in Isla Vista, which is on the opposite side of the campus from the Freshman dorms. All the UCs are big schools – at any UC there are going to be LOTS of partiers and LOTS of people who don’t party, the people you end up spending time with are going to be the people you want to spend time with.
I would greatly recommend UCSB (for engineering/CS)!