I recommend you take commerce 2fa3 BUT only take it with brewer! The people I know who took the course with deaves did mediocre to really bad which is not something I think you'd want! I took 2fa3 with brewer in the summer (pretty sure he teaches it every summer) and ended up with a 11 in the course. I think the course is much easier with brewer because you are not really required to read textbook or do textbook questions. All I did was read lecture notes and practise all previous tests, assignments and tutorials. What is great is that there is weekly quizzes which gives you a nice and easy 10% towards your final grade. Despite what people say about him, like he's boring or says uhhhh all the time he's a genuinely good and nice guy.
I got 7 in both 2aa3 and 2ab3. I was overconfident in 2aa3 because I took accounting in high school so didn't try as hard though I definitley think I could have done better if I tried harder (like practise all previous tests! I only did one or two D; ahh confidence i shoot you! ) In 2ab3 though I worked really hard because the material was new and completely different from 2aa3, but even when I exerted a full amount of effort I only ended with a 7 :(. I found 2ab3 much more difficult simply because I was putting so much effort in but only ended with a mediocre mark. By the way for 2aa3 and 2ab3 I had Aadil Juma who is a really good proffesor just I thought he was harder in 2ab3 then 2aa3.
Hope that helps with your decision