Toughest Win2K MCSE Exam?

I am interested in getting the opinions of the Win2K MCSE’s out there regarding the toughest of the core and design exams. I am considering taking a course for one of them, but don’t want to waste the class on easy stuff. I have been working with Win2K ever since it came out and self-studied for my NT MCSE, so I am reluctant to take classes if they are not needed. We have yet to migrate to AD, so I am considering focusing on that. Thanks for any advice.