Having known people who took this class with him last quarter, it is clear that Xu has made some solid improvements to the course, including having much more organized lecture notes, a more fair curve, and more straightforward communication as to what we will be tested on (everything tested is something from homeworks/lectures/extra practice). Some other changes include having one midterm instead of two, and a sympathetic grading policy ("comeback mechanic", final drops midterm score and becomes worth 85%). I was warned against taking this class with him, and his current 1.0 rating is probably reflective of his teaching/testing methods last quarter, however I think this class has improved significantly since then as I've definitely had worse professors here and there is nothing about my experience this quarter that stands out as particularly bad. He also ended up making the last 3 homeworks completion based since he fell behind the class schedule, which was greatly appreciated since they can take a while and it took some stress off of the last few weeks of the quarter.

Real analysis is hard in general but Peter seems like he genuinely wants to help and is really good at explaining concepts that weren't clear the first time around. Super nice guy and OH are extremely helpful. Offers alternative grading so if you bomb the midterm, it can get dropped which is huge.