Alexander is kind, funny, and approachable. He's also really into war crimes and human shields. It's the best of both worlds, really.
His teaching is equal parts tradition and invention. A lot of discussions will be descriptive. 2-3 breakout room sessions every class where you answer questions of the type "What does X say about Y". They vary in how stimulating they are – regurgitating arguments can be tedious, but sometimes you'll hit on an insight through that process of description that you wouldn't have otherwise. The papers and prompts are VERY conventional - yeah you'll get better at formulating arguments cogently (myeh myeh) but more importantly – if you want to spend 2400 words dropping hot takes, you can pitch your own prompt.
For the inventive aspect: our class on Descartes was phenomenal! It was a 2-hour long session debating the certainty of different facts. We didn't explicitly talk about Descartes through most of it, but that's immaterial - we were recreating his process of doubt and it felt like THE most concentrated sense of intellectual community any of my classes have been able to create yet. Alexander will sprinkle in similar thought experiments (+ Curb Your Enthusiasm clips) that are in my opinion the high points of the class. There's also a good dose of pop culture and contemporary politics in this class that isn't tainted with the Boomerian impulse to be relatable, if you know what I mean.
If you're looking for a very dialogic section, this is a great option. You will have a lot of freedom to take the discussion in the direction you want to. Alexander's prompts are open-ended enough to allow that. If you think the quality of conversation is dwindling, take the onus upon yourself to make it interesting! Say something controversial. Alexander will welcome it. I had an *amazing* group of peers who asked cool questions and resurrected even the dullest, droning pedants (read: Hobbes) from the dead.
He's also very open to feedback. He opened up an anonymous form mid-October and took a ton of our advice. This speaks a lot to his sensitivity – this was his first time teaching CC, and he's genuinely trying to make it a good experience for his students.