I did my undergrad degree at Davis and my boyfriend got his PhD there (so between us, we've spent many, many years in that valley town). In my experience, most people don't like it too much in the beginning, but it can be really fun once you meet people. The town is small, but people tend to have house parties and you can ride your bike to anywhere. There certainly are things that are annoying about it, but it is also friendly and safe. You run into the same people pretty often, so I found it easier to meet people and make friends there than when I did my master's in a larger city.
The people that complain the most tend to go back. I complained all the time and I still applied to go do a PhD there this fall.