Hempel is a good example of how knowledge in a subject doesn't directly indicate an ability to teach. She definitely knows the material well and, as a result, works at a pace that might be difficult for most students. As a transfer student, I can't say for sure whether such an accelerated pace is typical at UCLA but, for me personally, I found her pace to be fast.

As for HW, she uses homework from a previous instructor in 115A so getting high scores on HW is manageable. Midterms are doable (and oftentimes the practice exams reflect what is on the actual exams themselves). As for finals, she puts new information on the study guides and expects students to master it by the final.

Overall, Hempel isn't the greatest instructor. If you understand linear algebra incredibly well, then her class might be manageable. But if your overall understanding is grey in some areas and you don't back up each lecture with hours of studying, it might be difficult to catch up.

Whether you are strong in mathematics or not, I would not take Hempel for any math class. Although she is very nice, I would not consider her style of teaching as effective. The lectures consist of her writing on the board for the entirety of the class time. She usually has her back turned to the class and does not thoroughly explain concepts. To add to my last point, there is no book for the class and Hempel does not provide the notes before each lecture; making it difficult for students to go over any material before covering it in the lecture. Save yourself the stress and take someone else for Math 115A.