Prof Chernikov is a cool guy and I really enjoyed his math 115B class. During lecture, he teaches straight from the book. This was a good and bad thing in my opinion--good because I could re-read the book after lecture to ingrain the concepts in my head, but bad because I hate Friedberg's Linear Algebra book. Maybe I'm just not good at math but I really think that book is horrible. Anyways, Chernikov is funny and good at explaining concepts. He does go kind of fast, but its easy to go back and learn what you missed.
As a class, I would say 115B is fairly challenging, but that's what made it great. If you have the chance to take 115B, take it. And if you can get a class with Chrenikov, do it.