3 to 4 hours per assignment... But mainly that is for 1L classes which are harder to understand. When you become a 2L usually the classes are less pressure b/c for instance there isn't a mandatory Socratic method, but instead a sign up panel, so you usually feel more inclined to just read it and write in your book notes. My family law class has a lot of interesting cases and it is a quicker read plus we have a sign up panel where you only really really have to be called on for one week out of the year. I'm still taking Contracts and Property in the evening and they take forever and the information isn't as interesting and is more difficult so it take a lot longer, plus you have the panic factor of suprise socratic method. My second year classes are a lot easier, more relaxed and more interesting. Sadly i'm not looking forward to 3 1L classes next semester and 2 2L classes that are bar courses and still difficult. Evidence and PR.
In the end it depends on the classes you take, the Bar courses are more difficult than the non-bar courses, some people went insane during moot court but i didn't think it was that bad, the appellate brief only took me 5 days to write, for some it took weeks. For me i'm good at getting writen assignments done, reading is a slow and usually painful process for my eyes, i find it all interesting, but tedious torture all the same. I hope this helps explain the law school experience so far. Ciao