Morgan is brilliant! Take her for the best intro to upper div math; she covered 115AH material up to the spectral theorem, but also would add elements of abstract algebra, calculus, etc. to lectures/HW/office hours. You should go to office hours, even just to talk more deeply about class topics! Her lectures are extremely clear and logical, and she posts lecture notes before class (attendance is "mandatory", but you should go regardless of policy). HW is long but essential to your success in the class. Discussions are also mandatory and essential to the class (covers additional content). Her exams are extremely fair and have averages in the 80/90 range, and she offered a small amount of extra credit during the course as well!
Grading breakdown is forgiving with 20% per midterm and 25% final, and she also offers the "drop one midterm replace with final".
Overall, expect to pay your dues in terms of time commitment, expect HWs to take 10-15 hours per week (typeset in LaTeX), etc. but you'll be heavily rewarded. It's a fast-paced honors class after all, but she is a brilliant lecturer, so caring, funny, and clearly gives her all into teaching; you'd be crazy not to love her.

Professor Opie is hands down the best Math professor I've had in UCLA! The structure of the course is well-designed, as we started building from the foundations (proof techniques, sets, vector and quotient spaces, etc.) in the first 2 weeks, before diving into the crux of Linear Algebra. Her lectures are engaging as she has a witty sense of humor, and even if you miss lectures once in a while, her lectures notes are really helpful in self-learning/revision. Furthermore, exams are fair - there will be a few questions similar to the practice exams, whereas others will be more challenging. As long as you put in consistent effort, you will do well. The only downside is that homework assignments are long and must be typed out in latex, so I spent an average of 10-15 hours on each homework assignment. In hindsight, all the effort put in was worthwhile, as my proof-writing improved tremendously through all the practice. Discussion worksheets tied in perfectly with lectures too, filling in the gaps that we failed to cover during lectures due to time constraint (Joshua is a wonderful TA too). Overall, I would highly recommend any class with Morgan!

WONDERFUL WONDERFUL PROFESSOR. Morgan Opie is simply amazing and honestly all the other professors should be like her. I think most people got A's as the test averages were pretty high (80-90) and an A was well within reach for me but I got really sick during finals week and could barely study so I bombed my final but that doesn't take away from Morgan being the absolute goat. Morgan really cares about all her students (she tries to get to know everyone by name) and puts her heart and soul into teaching well. I wish she taught more upper divs as this class was a really great experience and I learned so much stuff. Homework was tough and time consuming, but pretty reasonable. Lectures are VERY ORGANIZED AND VERY CLEAR. She makes a very big effort to be clear and understandable, and makes sure that everyone is following along. She gives a lot of practice exams before midterms and final, which are pretty reflective of the real test. Attendance was technically 'mandatory' in the syllabus but since like most people didn't skip class she also didn't record attendance. Also office hours are super helpful and she is very welcoming and friendly if you need help. Cannot recommend Morgan more. 1000/10

Professor Opie is a great prof. for this class. She introduced proofs in a very accessible manner since this is many people's first proof-based class and explained each topic very well. The course is organized like most other math classes, but when I took it we had a required discussion section worksheet which was pretty helpful. She's also very nice and helpful, so don't be afraid to ask questions or go to OH. Wish I was better at math so I could take more courses with her!

Morgan was a great professor for Math 115A. For many, this would be the first proofs class for math and she knows that the proof methodology is difficult for many to grasp so she offers ample help in order to get students ready for writing their own proofs. Lectures are very organized and were done on iPad with the projector and she also recorded her lectures and broadcasted them on Zoom. Therefore, there was an option to watch the lectures remotely.
She makes an effort to know each of the students in the class since it is a smaller class and the discussions were well integrated with the lectures. Although the content and starting to write proofs is hard, she understands the mistakes that students are likely to make and does spend time helping those who need it. She is very helpful in office hours as well to the point where almost 1/3 of the class would attend these office hours. Exams were manageable if you keep up with the work and the homework but are a time crunch. Homeworks were a bit difficult and I spent a lot of time on them, but this is probably something that is universal among 115a classes.