UC Davis is a fine institution, but it is not a fit for everyone.  For me, the fit was actually pretty bad, but I got a lot of good things out of my experience there.  The kids who choose to attend UCD tend to be decent people - generally friendly and down-to-earth.  The majority will not blow you away with their smarts or their focus, and as an undergraduate that bothered me a lot, but there are smart students that you can find with some effort.  That's sort of a general theme of my experience: there are a lot of opportunities available, but there can be some hurdles to jump.  For example, class sizes are large, and it can be easy to feel neglected on an individual level, but I found faculty to be very approachable and helpful.  I think the professors do genuinely care about students, and if you show that you have real interest in the subject, they will do their best to help you.

But as I said before, UCD is not for everyone.  It is not a social hub (due partly to its location), its campus is not very impressive, and it is not (universally) a household name among schools.  If these are important considerations to you, you may not like life at UCD.  Also, although it is a major research university now, it still shows signs of its agricultural origins.  Aside from the cows on campus, it also appears in the selection of courses offered.  For example, there is no undergraduate business degree, and there is a general lack of finance and accounting courses, but there is an Agricultural and Resource Economics department.  Hmm.  These realities are simply part of UCD's identity, so take them into account if you are you considering UC Davis against other schools.