Too many HW assignments (16), he assigns too much work and does not grade it in time (midterm grades appear 4 weeks later, hw grades from week 3 appear week 10), TAs are useless, midterm 2 was challenging but it was curved. he isn't a harsh grader but some aspects could be improved. avoid him if you are not a CS major/interested in topic.
I don't understand the critical reviews. Matni is a clear lecturer, he answers questions and is somewhat active on Piazza. As long as you don't leave hw/labs to the last minute you should be OK. The first midterm average was about a 90, and he allowed a page of notes. He's approachable and knowledgeable about the subject material.
Lectures not very friendly towards CS beginners. Poor and little instructions on basic terminal commands and c++ editor. He prefers teaching with PPT than actual coding demonstration. TONS of work (2 written hws + 1 programming assignment per week). Exams are okay. Took me a lot of reading, googling, self-teaching to earned a good grade. AVOID!!!!
Avoid him if you can. Lots of confusions, too much work.