It actually works out better for me to read two at a time. At least for these first three sets of two, each book starts and finishes an arc, starts a second arc that is finished in the second book, and then one final arc which finishes up by the end of the second volume. It did get a bit long so b...
There's actually quite a bit going on here. The Kikyo cliffhanger is resolved (of course, her storyline isn't near done yet), Miroku gets added to the family, and Naraku is revealed as the real Big Bad of the series. Quite a lot of story for one volume. Miroku was never my favorite out of the InuYas...