This class with Kao, I would rank as one of the top I've taken at UCLA. This was the first time he taught signals and systems, but he came into class very well prepared every single day. He really cared about making sure everyone understands the material best they can by giving a lot of intuition to the things he's teaching, and he mentioned how when he was an undergrad he did badly on the first midterm due to a lack of intuitive understanding. He also tends to mention how he uses the tools in 102 in his own work in neural prostheses, which is actually super cool to hear about.

There was a small pacing problem near the beginning of the class, because he would answer everyone's question in detail even though that's literally the next slide, but he later corrected that issue. Homework was challenging but doable – which to be honest is what should be the case. The grading curve was very lenient and he is committed to give everyone as high a grade as possible.

Basically, Kao is the best professor to take 102 with.

I really enjoyed this class with Kao. The concepts are really interesting, and he does a great job of explaining intuition and applications (including to his own research). He is very thorough and doesn't go too fast, and treats the subject with about as much mathematical rigor as you can without being in an actual math class.
He created slides in advance, then annotated them in class and posted the annotated PDFs for us to download. I never had to refer to the textbook to understand the material.

Kao is also very accommodating to students. He will move office hours, make corrections to materials, email quickly, and is always happy to look up the answer to a question if he does not know the answer already.