Well, I just finished my second MCAD/MCSD exam, 70-320 XML Web Services. I'm glad it's all over cause I've been postponing this exam for quite some time now...I figure, why wait? Just get it over with!
I find myself questioning the way my self-paced book approached the different topics (Windows Services, Component Services, Web Services). I specially liked the fact the way the book implemented some ws examples that used DataSets. Why do I say this? Well, after reading Rocky's posts on passing DataSet objects through Web Services, I just have to chuckle at the examples and move on. Granted, these examples are intended for reader to learn the HOW rather than the HOW/WHY. But like with everything, you must keep an open mind. Also, Rocky is kind enough to post his feelings on Remoting, Web Services and COM+/DCOM, that once again make you ask yourself...why is the book doing it that way??!?!
Never the less, just learn the "glue method", and pass the test. Worry about making it perfect next time around.