Shuming consistently goes above and beyond for her students. I haven't had a single teacher or professor from elementary, middle, high school, or college as dedicated as her to teaching students. Her class is extremely tough-don't get me wrong, but she prepares students well for her exams.
The homework is more-or-less free points, and it's very similar to what is on exams. She gives two practice exams which are fairly representative, along with additional problem sets. You can also get up to 2% extra credit, but you'll need it. Again, the exams are really hard.
Most importantly, Dr. Chen herself does weekly review sessions in the evening, which contain even more practice and are highly useful. Her lectures are engaging, and very clear and useful.
However, only buy the modeling kit-you get to use that on exams. Otherwise, the book is practically useless; just pirate it as you won't read much from it.
Looking back after having taken Chem 30B with Merlic, her class really does give students the fundamentals to succeed in future courses. Her tests were definitely hard; I'd say that her synthesis problems were even harder than the ones I had to do in 30B, with over a dozen of steps compared to 5-6 max in 30B.