I am also taking the June 2007 Level I exam and will start preparing beginning of November. I spoke to a friend who took the exam five years ago, and she said that all she studied were the Schweser notes and passed the exam! However, since I have enough time, I have decided to buy the official CFA books, study them thoroughly, and then buy the Schweser notes to practice more problems to become good at problem solving (hopefully!). The reason I want to study both the book sets is because instead of just being able to solve problems, I want to make sure that I have an in-depth understanding of the materials that I am planning to devote most of my life into; especially since I do not have much of a background in Finance or Investment Management at this point (I have a BA and MA in Economics)! Like I said, since I have ample time, no harm can come out of it. My friend who studied only the Scheweser notes also said the same thing to me -- study both if you have time. By the way, ironically, she does not work in anything even remotely related to CFA or asset / investment management and she told me that she took the exam just for the heck of it since the company where she used to work was paying for it and everyone of her colleagues were taking it and she did not want to "lag behind".
The gist of all this, if you just want to pass the exam or otherwise have enough experience/background in the investment profession, I don't think you have anything to lose just by studying the study notes. I have seen this same advice coming out of many other successful, veteran test-takers in this board. But like I said above, you will only benefit if you study both sets. May be I will see you along the way in this board. Good luck!
-Ron-