Well, there are a lot of biased opinions on here, and mine will be no different. None of us have worked at all of the Cali programs, so comparing them all is trivial. What we can all do and mostly have done is discuss the plusses and minuses of each place we worked, not just heard through this website. I'll give you my opinion as unbiased as possible on each of the places I rotated at.
The other issue I'll address first because few discuss it, is why we argue about what's the best Cali program to go to? I'll start with a quote from a recent conversation with a west coast chairman, "I don't understand what all the fuss is about the west coast programs. There are numerous better programs in the Midwest and east coast that get far less attention." I mentioned this because I've received the impression, and I'm guessing several others have too, that certain Cali programs are great, UCD for example. While I do agree, it's important to keep in perspective the reasons why we choose a residency. Anyone that wants to get a top-notch training should not come to Cali. While the programs here are good, there are clearly others that are superior. Even the best, perhaps UCD, doesn't compare to the best programs in the Midwest and east coast. Now with that said, having been born and raised in Cali, I'd do just about anything to get back. The bottom line, weather is priceless. There is no amount of money I wouldn't pay for a home in Cali in order to have year round comfortable weather. To be able to play golf in January, cycle in February, and ski in March, it's worth millions over a lifetime. I would gladly pay an extra few hundred thousand dollars for no freezing cold winters and no hot and humid summers. (Many Californians are sick of people crowding us and raising house prices, so they send out negative vibs about the area. I think my opinions are representative for how most of us really feel though).
UCD - I rotated here on the trauma service and unlike everyone else I don't think they are all that trauma heavy. They only rotate on the trauma service 1 or 2 months as interns, 6 months as 2's, 3 months as 3's, and 3 months as chiefs. Compared to USC where they do 21 months of trauma, UCD's 13 months doesn't seem heavy to me. Granted, the trauma service is busy, their morning triage is run by trauma attendings, and you'll work hardest on the trauma service, but at least from what I saw all the juniors left after 24 hours on call and only took call every 4-5 nights. More importantly the only ortho resident that takes call is the trauma junior, i.e. - do I need to do the math for you, you have no call for almost 3 years of your residency, that's as priceless as the Cali weather. The guys and gals here are great, and seem very happy. They have a well-rounded experience, and almost all of the attendings are cool. Like everywhere, there are negatives though. My best example is one day when I ended up being the sixth, yes 6th, assistant on a case. The entire team was scrubbed in, the attending, fellow, chief, 2 juniors, the intern, and myself. Needless to say I could barely see and this gave me a bad taste, but fortunately that isn't common, and in the end I will still likely rank them number 1. Furthermore, having grown up in a town of 150 K, living in Sacramento isn't as bad as many it make out. There are dozens of superb restaurants, several nightclubs, a load of cool bars, and tons of outdoor activities to do. Furthermore, you're only 90 minutes from SF and 90 minutes from the Tahoe, so there is always something fun to do during your brief moments of spare time. It's probably a better place for applicants with families rather than singles/couples, but either way you can be happy as long as you're not longing to be in middle of a huge city.
San Francisco Orthopedic Residency Program (St. Mary's)- Small tight-knit program. Deemed cushy because all five years are home call, and while at St. Mary's you rarely need to go in. On the other hand, because it's small, when you're at Kaiser Oakland or Highland Hospital in Oakland you can be there all night by yourself, and because you're home call doesn't count toward the eighty-hour week, you can end up working a pretty grueling schedule while at these hospitals. Also, one of your two 3-month peds rotations is at Shriners in Sac, so you'll be away from home for a while in your 5th year. With that said, they are all still very happy and they all believe they have it easy. They end up doing ~1500 cases in 5 years; from what I've seen and heard this is very respectable with the 80 hour work week and the reputation of a cushy program. They get great hands-on, personal training, and I guarantee they are never more the 2nd or 3rd assist on any case, usually primary or 1st assist. The residents are all extremely fun loving, easy going guys and gals, and they are all very happy there, it was almost everyone's 1st choice. ~15 rotate, 5 of which get interviews. Another 5 random applicants get interviews, and then they take 3 of the 10 interviewed. They only went to 5 on their rank list last year. The negatives: They are a tiny program with minimal didactics, and minuscule research (don't go here if you care about this). They have a new chairman for the first time in 30 years with a few other potentially significant changes, and St. Mary's is less than dedicated to education, both of which gave me an uneasy feeling of instability. Obviously I'm geographically biased, but if it wasn't for the instability I would rank them No. 1. Taking the instability into account, I'll likely rank them #3 or 4.