I agree that this book has a lot to offer. I also agree with everyone who notes that you need to read it several times to catch on with his "lessons." They're good, but sometimes difficult to discern.
I guess this removes any doubt about my level of riding experiene, but I was unaware of the concept of shifting without using the clutch. I tried it this weekend and it works really well--much smoother, no awkward loss of rpm's or power. Is this something used only on the racetrack, or can the rest of us use it safely? Anyone have any concerns?