I was very happy with my Carezza, but not until I got a Mazzer Mini. Before that I tried a $100 Breville grinder, and later a Rancilio Rocky. Acceptable results, but not "good" until the Mazzer. Later I upgraded the Carezza to one of the hulking E61 machines everyone talks about around here. Guess what, it's more fun to use but the coffee did not drastically improve (compared to the grinder upgrade).
Now... onto the barista skills and coffee. You are fortunate to live in Southern California... if I were you I would make the 2 hour drive out to Venice Beach and go to the Intelligentsia shop there. You can watch the baristas do their thing, try some great espresso, buy some great beans, and
even take a barista training class.
Check it out.If you do all of those things, you can probably leap forward several months in your espresso understanding.
Also, don't miss Klatch Roasting in the San Dimas area -- they
also do training (not sure how much it costs or whether it is oriented to consumers), they have some
great espresso blends,
and they are closer to you than Intelligentsia.