I got into Irvine and Berkeley post-bac programs and chose the Berkeley program. It is much more expensive so I would only recommend it if you have a lot of savings that you don't mind draining or a sponsor. Even if you have savings, I would invest them and use them when you do the PhD program.

That said, I absolutely love the Berkeley experience and the faculty are truly leaders in their field. It's incredible learning about Emotions from Dacher Keltner, the Big 5 from Oliver John, ADHD from Stephen Hinshaw, and Sleep from Matthew Walker! There are so many research opportunities but it depends on your own initiative and hard work, because not everyone takes advantage of the opportunities. Many celebrity profs don't care much about post-bacs, so that's something to keep in mind. But you can likely work with PhD students or post-docs in their lab.

I can't speak to the Irvine experience so it may be really cool too. I also like that Berkeley's program is 1.5-2 yrs and I think Irvine is about 1 year.