Kui Ren is a fantastic professor. He's super nice, a great teacher, down-to-earth (albeit a bit shy), and has an all-around good introductory complex variables course. I personally feel he's one of the best professors at the school, especially if you are not a quick learner. He is readily available for office hours and explains every single step so thoroughly but efficiently that he could teach a toddler complex variables.
The two classes, MATH3007 and APMA4204, are equivalent and the math department views them that way as well. When I took the class, Kui Ren used Gamelin Complex Variables and Fokas Complex Variables. It's not Honors Complex (Ahlfors), if that's what you're looking for. The grading is really nice. He's a tad harsh on the 1st midterm, but he generously re-weights tests and homework and doesn't try to hurt you.
The workload is one problem set per week and Kui Ren covers both theory and applications equally without compromising either. He uploads lecture notes for each class online and posts worked-out solutions to all homework and midterms, plus sample midterms.
The one downside is he talks really slowly, says "um" a lot and swears during class when he makes a mistake or says something in a way he deems to convoluted. For some people it can seem like he doesn't know what he's doing, and I saw people judged him from that impression.