As an instructor, I am using Canvas for the 1st time this semester and a few students have mentioned that they feel Canvas is less friendly than other online interfaces they have used, although they have mentioned no specifics as yet. I will soon attempt to find out what else they find less user friendly.
I have also taught online classes using WebCT, Moodle, and Santa Rosa Junior College's online interface, called CATE.
I feel that discussion lists in Canvas are problematic, as one has to scroll though all the posts of a list to find the one that you're looking for. This makes it somewhat of a hassle, especially once the list grows fairly large. Another issue is the first input entry in a list in which someone makes an original post should NOT say 'reply' but instead say 'new post' or something similar. I have set up the lists as threaded and mentioned this to the students, but some students are using this first box to reply to a posted message that comes later.
I think instead, the canvas designers should simply have had links on a discussion list (similar to Moodle and Cate), with the author's name and subject depicting it and then clicking the link would bring up the post. This approach certainly would make it easier to find a particular post.
Instructor at Santa Rosa Junior College