Prof. Hallak is great. Funny, with a slight Argentinian accent and a friendly demeanor, he liked to know everyone's name and involve the students in the class. Models were generally well-taught and Prof. Hallak was very approachable.
The course is very model-heavy: the first half dealt with the Ricardian and Heckscher-Ohlin models, which served as a reference point for all later lectures, and the rest involved the specific factors model, tariffs (similar to what you do in Principles but a bit more rigorous), monopolistic competition and the feared Melitz model (brrr). The nice thing is that Prof. Hallak also likes to involve some more "empirical" learning, which mostly involves reading and discussing papers. This is a nice idea and made for some very good lecture moments, but it stalled sometimes unfortunately, and feels like something of a missed opportunity.
The class is relatively light for the economics department- roughly semiweekly problem sets (6 in total, graded on check-check plus-check minus basis), which are pretty standard fare, plus a midterm and final, both of which were very reasonable and even on the easy side.
I am a little ambivalent about what you can expect to take away from this class. The models are taught well, but they're models, so they don't add all that much to your understanding of the world. And while the empirical aspect of the course was a welcome departure from that trend, it didn't consist of much more than just going through articles. So the idea is good, but in the end the material to me seems rather forgettable, though it was largely an enjoyable experience.
The TA, Goran, was excellent. Sometimes he tried to hard to demonstrate mathematically rigorous proofs and theorems, but he was very approachable, was great at explaining concepts and clearly cared a lot about his students.