Slater is a nice guy and a good teacher. He assigns great papers to read and leads discussion well but occasionally it would be helpful if he'd zoom out and summarize the different positions on key topics -- I found that students who'd taken Epistemology with other instructors didn't have the grasp of a number of specific areas I did, sometimes tough ones (I'm not sure, but I don't think Quine's _Two Dogmas_ is usually the sort of thing you get in an introductory class) but they could summarize things off the top of their heads that I had to sit down and think through and occasionally check other sources to be sure I had the full view of.
Some instructors in Philosophy give short take-home questions meant to force the students to work through this kind of issue. Something like that might have fixed the one minor complaint I have with Slater's teaching style -- as hard as it is to really suggest that an instructor give more work!
All in all a good teacher.
Two short papers or one long one. A question about the reading before every class.