FWIW one of our professors here at uwaterloo taught a first year abstract algebra / number theory class in a very Lockhart-esque way (Math 145; he even quoted L

FWIW one of our professors here at uwaterloo taught a first year abstract algebra / number theory class in a very Lockhart-esque way (Math 145; he even quoted Lockhart on one of the assignments). I learned a lot of math and enjoyed myself, but the main problem I observed was figuring out how to fairly grade students, and the fact that the homework took a lot more time than a class taught normally.